207 + Mcqs in Bank PO Exams Page 4 McqOptions

151.	Three friends A, B, and C started a business and invested in the ratio of 8: 6: 15. At the end of one year out of the total profit ofRs. 6000, A’s share was Rs. 2000 which was Rs. 500 more than that of B’s share. Find the ratio of time for which they had contributed their capitals?
A.	1 : 1 : 2
B.	5 : 5 : 3
C.	3 : 3 : 2
D.	6 : 6 : 5
E.	None of these
Answer» D. 6 : 6 : 5

Discussion

152.	A bond gets matured in 10 years. Ram invested Rs. 42000 in this bond and received Rs. 105000 once the bond matured. If the bond was under simple interest, then what was the rate of interest per annum ?
A.	10%
B.	12.5%
C.	15%
D.	7.5%
E.	None of these
Answer» D. 7.5%

Discussion

153.	A and B start swimming simultaneously towards each other from the point P and Q respectively. After 12 hours, they meet each other after that A takes 6 hours 40 minutes more to reach the point Q . What is the ratio of the speed of A in still water to that of the speed of stream if it is given that the direction of flow of the river is from point P to Q and in still water the ratio of the speed of A to that of B is 7 : 5?
A.	7 : 5
B.	35 : 6
C.	49 : 5
D.	42 : 5
E.	None of these
Answer» D. 42 : 5

Discussion

154.	Vicky invited some of his friends for a party. 20% of them came by car and 40% of the remaining came by Bike. The number of friends who came by bus is 50% more than that by car and if 36 friends came by auto then total how many friends came by Bike? (assume that all came by any one of the vehicles car, bike, bus or auto)
A.	72
B.	60
C.	64
D.	50
E.	None of these
Answer» D. 50

Discussion

155.	Tenali Ram purchased 150 chocolates for his 5 grandsons and distributed the chocolates in such a way that the number of chocolates received by each grandson is in arithmetic progression. The highest number of chocolates received by any one of them is 28 more than the lowest number of chocolates received by any one of them. What is the sum of highest number of chocolates received by any one of them and the lowest number of chocolates received by any one of them?
A.	50
B.	60
C.	40
D.	70
E.	None of these
Answer» C. 40

Discussion

156.	Two motorboats A and B, start simultaneously from the two ends P and Q of a river in downstream and upstream respectively. The speed of the motorboat A in still water is 200% more than that of motorboat B. If the distance between P and Q is 120 Km and they meet each other after 5 hours then how long the motorboat A will take to travel 90 km in still water?
A.	6 hours
B.	5 hours
C.	8 hours
D.	None of these
E.	Can't be determined
Answer» C. 8 hours

Discussion

157.	When Ram was asked his age then he being good in reasoning, said that my age before 5 years was one – twentieth of my father’s present age. 12 years hence, I will get married and my wife’s age will be three times of my present age. After 2 years of marriage, I will get a baby and the average age of my family will become 18.5 years. What will be Ram’s father age when he gets a baby?
A.	36 years
B.	44 years
C.	28 years
D.	34 years
E.	None of these
Answer» E. None of these

Discussion

158.	The area of the square ABCD is 784 sq. cm. If a circle was drawn inside the square, the circumference of which touch all the sides of square as shown in the figure given below then what is the area of the shaded region?
A.	168 sq cm
B.	172 sq cm
C.	112 sq cm
D.	84 sq cm
E.	None of these
Answer» E. None of these

Discussion

159.	A person can complete a job in 150 days. He started the job alone but after 20 days, he was joined by another person who also can complete the job in 150 days and before 30 days of complication of work, they were joined by a third person of same efficiency. In how many days the work was completed?
A.	75 days
B.	80 days
C.	70 days
D.	50 days
E.	None of these
Answer» D. 50 days

Discussion

160.	In Mohenjo-Daro, when percentage was not in use, a merchant sold the products as buys 5 get 3 free or buy 15 get 5 free plus free transportation. The expenditures on transporting 20 products is equal to the marked price of 5 products. In today scenario, what is the difference between the percentage of discount offered by the merchant?
A.	15%
B.	37.5%
C.	12.5%
D.	13%
E.	None of these
Answer» D. 13%

Discussion

161.	The ratio of boys to girls in a school was 2 : 3. When 20 girls left the school, then the ratio of boys to girls becomes equal. In what ratio, 140 boys and girls should have joined the school before leaving the girls to make the number of girls 50% less than that of boys?
A.	4 : 3
B.	5 : 2
C.	9 : 5
D.	6 : 1
E.	None of these
Answer» E. None of these

Discussion

162.	The average weight of a group of girls is 20 kg less than that of a group of boys. If the number of girls is 10 less than that of boys and the average weight of boys is 50 kg and the combined average weight is 45 kg then the sum of the weight of boys is how much more than that of girls?
A.	750 kg
B.	600 kg
C.	400 kg
D.	800 kg
E.	None of these
Answer» C. 400 kg

Discussion

163.	Ram and Rahim started a joint business. The initial investment of Ram was thrice that of Rahim’s initial investments and period of Rahim’s investments was four times than that of Ram’s period of investments. If the difference between the profit of Ram and Rahim was Rs. 4500 then what was the 50% of total profit?
A.	Rs. 18000
B.	Rs. 15750
C.	Rs. 11250
D.	Rs. 16250
E.	None of these
Answer» C. Rs. 11250

Discussion

164.	A man purchased some goods and marks the price 20% above the cost price. If he sells one third of the goods at the discount of 5% on the marked price then what percentage of discount should he offer on the marked price of remaining goods, if he desires to earn total 8% profit on the cost price?
A.	12.5%
B.	12%
C.	7.5%
D.	15%
E.	None of these
Answer» B. 12%

Discussion

165.	The speed of a motorboat in upstream is 12 km per hour while river is flowing with a speed of 2 km per hour. If the motorboat takes 3 hours more to travel x km in still water than to travel x – 24 km in downstream. Find the value of x?
A.	154 km
B.	168 km
C.	175 km
D.	182 km
E.	None of these
Answer» C. 175 km

Discussion

166.	In a class of 180 students, each student got chocolates that were 15% of the total number of students. If the number of chocolates is 20% more and the number of students is 10% less, then how many chocolates per student can be distributed?
A.	40
B.	32
C.	30
D.	42
E.	None of these
Answer» F.

Discussion

167.	A sum of money increases every year 1/8 times. At the end of 3 years, the sum of money become Rs. 4556.25 then what was the total increase in the first two years?
A.	Rs. 950
B.	Rs. 800
C.	Rs. 1025
D.	Rs. 850
E.	None of these
Answer» E. None of these

Discussion

168.	Pipes A and B together can fill a water tank in 18 hours, pipes B and C together can fill the same tank in 20 hours, and pipes A and C together can fill the same tank in 12 hours. If all the three pipes A, B, and C are opened together then they fill 51 litres of water per minute. Find the capacity of the tank (in litres)?
A.	32400
B.	34200
C.	27000
D.	30600
E.	None of these
Answer» B. 34200

Discussion

169.	The distance between Delhi and Patna is 588 km. Train P leaves from Delhi for Patna at speed of x km per hour and at the same time Train Q leaves from Patna for Delhi at speed of (x + 9) km per hour. At the end of 12 hours, they meet each other then find the speed of the train Q?
A.	23 km per hour
B.	25 km per hour
C.	20 km per hour
D.	27 km per hour
E.	None of these
Answer» F.

Discussion

170.	Three friends A, B, and C entered into a business. The ratio of there respective investments was 4 : 5 : 6. At the end of 4 months from the starting A withdraws 25% of his initial investment but C puts 50% more of his initial investment. At the end of one year, B’s share in total profit was Rs. 15000 then find the difference between A’s share and C’s share in the total profit?
A.	Rs. 8400
B.	Rs. 7800
C.	Rs. 8100
D.	Rs. 9000
E.	None of these
Answer» F.

Discussion

171.	Karina invested Rs. 50000 in a bank under simple interest. The maturity duration was 10 years and the bank had offered 10% per annum simple interest. At the end of 8 years, because of financial problem Karina withdraws all her amount but the bank gave her a lower rate of interest. If she gets Rs. 25000 less than what she would have got at the end of 10 years ,then find the lower rate of interest given by the bank?
A.	7.5%
B.	8.5%
C.	6.5%
D.	6.25%
E.	None of these
Answer» E. None of these

Discussion

172.	In a Cricket match, 5 players - A, B, C, D, and E play equal number of balls but score 48 runs, 58 runs, 98 runs, 78 runs, and 113 runs respectively. If the strike rate of all the five players together is 158 then find the number of balls played by each player?
A.	75
B.	100
C.	50
D.	125
E.	None of these
Answer» D. 125

Discussion

173.	Sunil and Sushil together started a business with investment of Rs. 22400 and Rs. 25600, respectively. After a year, Sunil increased his investment by 15% while Sushil decreased his investment by 25% with respect to the previous year. If the total profit at the end of 2 years was Rs. 20750, then find the profit share of Sunil.
A.	Rs. 10250
B.	Rs. 10750
C.	Rs. 9580
D.	Rs. 11200
E.	Rs. 9500
Answer» C. Rs. 9580

Discussion

174.	A pipe fills a cubical tank at the rate of 72 m3 per minute in 24 minutes. If a cylindrical tank having height same as the side of a cubical tank and the curved surface area of the cylindrical tank is 1056 m2 , then find the difference between the volumes of cylindrical tank and cubical tank.
A.	5242 m3
B.	5664 m3
C.	5568 m3
D.	5420 m3
E.	5380 m3
Answer» C. 5568 m3

Discussion

175.	A and B alone can do a work in 24 days and 32 days, respectively. A starts the work and worked alone for first 3 days and then B joined A. B and A together do the work for next 3 days and then another person C joined both. If the total work was completed in 13 days, then in how nay days A and C together can complete the work together?
A.	12 days
B.	16 days
C.	15 days
D.	10 days
E.	18 days
Answer» C. 15 days

Discussion

176.	The population of a city in the year 2016 is 8% more than the population of the same city in the year 2015. In July 2016, 12% of total population migrated to a different city and in the month of December 75% of them returned again in the city. If the population in the city in 2015 was 3 lakh, then what was the population of the city in the beginning of 2017?
A.	235710
B.	342520
C.	178870
D.	314280
E.	288450
Answer» E. 288450

Discussion

177.	Abhishek deposited a certain amount on compound interest at 10% per annum in a bank. But after two years he debited Rs. 465 from the bank. If the total amount received after four years was Rs. 23,595 then find the interest he got in first three years.
A.	Rs. 5218
B.	Rs. 5415
C.	Rs. 5620
D.	Rs. 5564
E.	Rs. 5365
Answer» C. Rs. 5620

Discussion

178.	The population of a city increases 12% every year while the population of males increases by 10% every year. The total population of the city becomes 75264 in 2 years while the total number of males in 2 years has increased by 7434. Find the number of females in the city 2 years before.
A.	25800
B.	24600
C.	22500
D.	23200
E.	28900
Answer» C. 22500

Discussion

179.	The time taken by Manan to travel 540 km is 4.5 hours less than the time taken by Vishal. If Vishal would have increased his speed by 20% then he would have travelled the same distance in 3 hours less. Find the speed of Manan.
A.	40 km/h
B.	45 km/h
C.	50 km/h
D.	20 km/h
E.	3 km/h
Answer» B. 45 km/h

Discussion

180.	The ratio of the present age of Komal and the present age of Priya is 2 : 3, respectively and the ratio of the present age of Priya and the present age of Rahul are 2 : 3 respectively. After 15 years, Rahul dies and at that time the age of Komal becomes the 7/9 of the age of Priya. Find the age of Rahul at the time of his death.
A.	90 years
B.	75 years
C.	60 years
D.	80 years
E.	100 years
Answer» D. 80 years

Discussion

181.	Manish and Pritam started a business with an investment of Rs. 5400 and Rs. 6500 respectively. After one year, Manish increased his investment by 20% while Pritam decreased his investment by 10%. If at the end of two years, the total profit in the business was Rs. 62998, then find the difference between the profit of Manish and the profit of Pritam.
A.	Rs. 1284
B.	Rs. 1148
C.	Rs. 1570
D.	Rs. 1222
E.	Rs. 1420
Answer» E. Rs. 1420

Discussion

182.	The average number of books sold in a week is 244 . The average number of books sold from Monday to Thursday is 252, average number of books sold on Tuesday and Wednesday is 207. If the average number of books sold from Thursday to Sunday is 272.5, then find the number of books sold on Monday.
A.	215
B.	191
C.	204
D.	218
E.	None of these
Answer» D. 218

Discussion

183.	Satyam and Shubham together can do the twice of a work in 12 days and Pawan alone can do the same work in 5 days. Pawan is thrice as efficient as Satyam and Satyam takes 5 more days than Shubham to do the work alone. In how many days can Shubham alone do the work?
A.	15 days
B.	8 days
C.	5 days
D.	7 days
E.	10 days
Answer» F.

Discussion

184.	A container contains mixture of water and alcohol in the ratio 9 : 4 respectively. A person sold some mixture at Rs. 15 per litre and earned Rs. 390 and then added 4 litres of alcohol in the mixture and the ratio of water and alcohol became 2 : 1 respectively. Find the amount of water present in the container initially.
A.	90 litres
B.	180 litres
C.	45 litres
D.	120 litres
E.	100 litres
Answer» B. 180 litres

Discussion

185.	Harish and Shivam together started a business with total investment of Rs. 2 lakh. The amount invested by Harish is 50% more than that of Shivam. If both Harish and Shivam increased their investments by 20% and 30% respectively in the next year and there is profit of Rs. 33600 at the end of second year, then find the profit of Shivam.
A.	Rs. 13800
B.	Rs. 19200
C.	Rs. 12000
D.	Rs. 18200
E.	Rs. 14900
Answer» B. Rs. 19200

Discussion

186.	Two pipes P and Q together can fill a tank in 35/6 minutes. Another two pipes i.e. pipe R having efficiency twice of pipe P and pipe S having efficiency half of pipe Q can together fill the same tank in 140/33 minutes. Find the ratio of the time taken by pipe P and the time taken by pipe Q alone to fill the tank.
A.	7 : 9
B.	3 : 4
C.	5 : 7
D.	Can't be determined
E.	None of these
Answer» D. Can't be determined

Discussion

187.	A cuboidal container having length, breadth and volume as 16 m, 13 m and 2080 m3 respectively is completely filled with water. A rod which has the shape of cylinder is immersed completely into the container in 55 sec due to which water flows out at the rate of 7 m3 per sec through an outlet pipe present in the container. Find the radius of the rod, if height of the rod is same as the height of cuboidal container.
A.	5.6 m
B.	4.2 m
C.	3.5 m
D.	2.1 m
E.	None of these
Answer» D. 2.1 m

Discussion

188.	The area of a rectangle is thrice the area of a circle. If the area of the circle is 616 sq. cm and the length of the rectangle is equal to the radius of the circle, then what is the perimeter of the rectangle?
A.	292 cm
B.	308 cm
C.	284 cm
D.	306 cm
E.	None of these
Answer» B. 308 cm

Discussion

189.	The initial investments of Anurag, Anu, and Sippy was 7 : 9 : 12 respectively. At the end of two years, they share the profit in the ratio of 14 : 21 : 32 respectively. If Sippy had invested for 2 years, then find the difference between the duration for which Anurag and Anu had invested?
A.	2 months
B.	6 months
C.	9 months
D.	4 months
E.	None of these
Answer» F.

Discussion

190.	If a total of 'N' number of 5 rupee coins were distributed among three boys A, B, and C in the ratio of 4 : 5 : 7 respectively ,then the amount received by C was Rs. 40 more than that of B . What was the average of the amount received by A and B?
A.	Rs. 36
B.	Rs. 90
C.	Rs. 45
D.	Rs. 180
E.	None of these
Answer» C. Rs. 45

Discussion

191.	A shopkeeper purchases a toy for Rs. 900. He marks the price of the toy in such a way that after allowing x% discount on the marked price he makes 10% profit but after allowing 2x% discount on the marked price he makes 40% loss. What is the marked price of the toy?
A.	Rs. 1440
B.	Rs. 1460
C.	Rs. 1280
D.	Rs. 1350
E.	None of these
Answer» B. Rs. 1460

Discussion

192.	A motorboat takes x hours to travel 900 km in downstream and it takes y hours to travel the same distance in upstream. If the speed of the stream is 2 km per hour and the speed of the motorboat in still water is 8 km more than the speed of the stream, then find the sum of x and y?
A.	175.5 hours
B.	175 hours
C.	192.5 hours
D.	187.5 hours
E.	None of these
Answer» E. None of these

Discussion

193.	A merchant fixes the selling price of an article Rs. 1260 after adding 20% profit on the cost price. As sales were very low at this price, he decided to issue a gift card free of cost to every customer which will give 10% cashback of total shopping amount. If the cost of each card was Rs. 10 then how much profit the merchant made on each article after giving 10% cashback and adding the cost of gift card on that cashback?
A.	Rs. 94
B.	Rs. 74
C.	Rs. 84
D.	Rs. 104
E.	None of these
Answer» C. Rs. 84

Discussion

194.	The average monthly income of five earning members of a family was Rs. 12850. One member passes away then the employer started paying 25% of his monthly salary to the family. If the earning members of the family divided equally that money among themselves then after adding that amount with their monthly income, the average monthly income of remaining four members of the family become Rs. 9050. What was the share of each member?
A.	Rs. 9350
B.	Rs. 9680
C.	Rs. 2337.50
D.	Rs. 2420
E.	None of these
Answer» D. Rs. 2420

Discussion

195.	A group of some boys met in a mango farm and pooled some mangoes in a bag such that each boy contributed exactly 4 mangoes more than the number of boys in the group. If each boy had contributed exactly 2 mangoes less than the number of boys in the group then the total number of mangoes would be 50% less than the first case. Find how many mangoes they would have pooled if each boy contributed exactly 2 mangoes more than the number of boys in the group?
A.	48
B.	24
C.	120
D.	80
E.	None of these
Answer» E. None of these

Discussion

196.	When A and B work together then they take 4 hours to complete a piece of work. When B alone works at 75% of his efficiency then he takes 8 hours to complete half of the piece of work. Find the number of hours A alone will take to complete the piece of work if he works at 75% his efficiency?
A.	8 hours
B.	6 hours
C.	9 hours
D.	4.5 hours
E.	None of these
Answer» B. 6 hours

Discussion

197.	A number is drawn at random from first 100 natural numbers. What is the probability that the number is not a prime number?
A.	1 2
B.	1 4
C.	6 25
D.	3 4
E.	None of these
Answer» E. None of these

Discussion

198.	A motorboat goes some distance downstream in 2x hours but it returns only 75% of the previous distance in 1.75x hours. What is the ratio of the speed of the motorboat in still water to the speed of stream?
A.	5 : 1
B.	7 : 1
C.	13 : 1
D.	9 : 2
E.	None of these
Answer» D. 9 : 2

Discussion

199.	A and B together invested in a business in the ratio of 5 : x respectively. At the end of 6 months, B withdraws 25% of his initial investment but at the end of 1 year, B’s share in profit was 40% more than that of A. What was the value of x?
A.	4
B.	8
C.	10
D.	7
E.	None of these
Answer» C. 10

Discussion

200.	Two persons A and B working together can complete a piece of work in 15 days but a third person C can destroy half the completed work in 15 days. In how many days A, B, and C working together can complete one fourth of the piece of work?
A.	8.5 days
B.	12.5 days
C.	10 days
D.	7.5 days
E.	None of these
Answer» E. None of these

Discussion

Explore topic-wise MCQs in Mixed Quant Quizzes.

Three friends A, B, and C started a business and invested in the ratio of 8: 6: 15. At the end of one year out of the total profit ofRs. 6000, A’s share was Rs. 2000 which was Rs. 500 more than that of B’s share. Find the ratio of time for which they had contributed their capitals?

A bond gets matured in 10 years. Ram invested Rs. 42000 in this bond and received Rs. 105000 once the bond matured. If the bond was under simple interest, then what was the rate of interest per annum ?

The area of the square ABCD is 784 sq. cm. If a circle was drawn inside the square, the circumference of which touch all the sides of square as shown in the figure given below then what is the area of the shaded region?

A person can complete a job in 150 days. He started the job alone but after 20 days, he was joined by another person who also can complete the job in 150 days and before 30 days of complication of work, they were joined by a third person of same efficiency. In how many days the work was completed?

The ratio of boys to girls in a school was 2 : 3. When 20 girls left the school, then the ratio of boys to girls becomes equal. In what ratio, 140 boys and girls should have joined the school before leaving the girls to make the number of girls 50% less than that of boys?

The average weight of a group of girls is 20 kg less than that of a group of boys. If the number of girls is 10 less than that of boys and the average weight of boys is 50 kg and the combined average weight is 45 kg then the sum of the weight of boys is how much more than that of girls?

A man purchased some goods and marks the price 20% above the cost price. If he sells one third of the goods at the discount of 5% on the marked price then what percentage of discount should he offer on the marked price of remaining goods, if he desires to earn total 8% profit on the cost price?

The speed of a motorboat in upstream is 12 km per hour while river is flowing with a speed of 2 km per hour. If the motorboat takes 3 hours more to travel x km in still water than to travel x – 24 km in downstream. Find the value of x?

In a class of 180 students, each student got chocolates that were 15% of the total number of students. If the number of chocolates is 20% more and the number of students is 10% less, then how many chocolates per student can be distributed?

A sum of money increases every year 1/8 times. At the end of 3 years, the sum of money become Rs. 4556.25 then what was the total increase in the first two years?

The distance between Delhi and Patna is 588 km. Train P leaves from Delhi for Patna at speed of x km per hour and at the same time Train Q leaves from Patna for Delhi at speed of (x + 9) km per hour. At the end of 12 hours, they meet each other then find the speed of the train Q?

In a Cricket match, 5 players - A, B, C, D, and E play equal number of balls but score 48 runs, 58 runs, 98 runs, 78 runs, and 113 runs respectively. If the strike rate of all the five players together is 158 then find the number of balls played by each player?

A pipe fills a cubical tank at the rate of 72 m3 per minute in 24 minutes. If a cylindrical tank having height same as the side of a cubical tank and the curved surface area of the cylindrical tank is 1056 m2 , then find the difference between the volumes of cylindrical tank and cubical tank.

Abhishek deposited a certain amount on compound interest at 10% per annum in a bank. But after two years he debited Rs. 465 from the bank. If the total amount received after four years was Rs. 23,595 then find the interest he got in first three years.

The population of a city increases 12% every year while the population of males increases by 10% every year. The total population of the city becomes 75264 in 2 years while the total number of males in 2 years has increased by 7434. Find the number of females in the city 2 years before.

The time taken by Manan to travel 540 km is 4.5 hours less than the time taken by Vishal. If Vishal would have increased his speed by 20% then he would have travelled the same distance in 3 hours less. Find the speed of Manan.

The average number of books sold in a week is 244 . The average number of books sold from Monday to Thursday is 252, average number of books sold on Tuesday and Wednesday is 207. If the average number of books sold from Thursday to Sunday is 272.5, then find the number of books sold on Monday.

Satyam and Shubham together can do the twice of a work in 12 days and Pawan alone can do the same work in 5 days. Pawan is thrice as efficient as Satyam and Satyam takes 5 more days than Shubham to do the work alone. In how many days can Shubham alone do the work?

The area of a rectangle is thrice the area of a circle. If the area of the circle is 616 sq. cm and the length of the rectangle is equal to the radius of the circle, then what is the perimeter of the rectangle?

The initial investments of Anurag, Anu, and Sippy was 7 : 9 : 12 respectively. At the end of two years, they share the profit in the ratio of 14 : 21 : 32 respectively. If Sippy had invested for 2 years, then find the difference between the duration for which Anurag and Anu had invested?

If a total of 'N' number of 5 rupee coins were distributed among three boys A, B, and C in the ratio of 4 : 5 : 7 respectively ,then the amount received by C was Rs. 40 more than that of B . What was the average of the amount received by A and B?

A shopkeeper purchases a toy for Rs. 900. He marks the price of the toy in such a way that after allowing x% discount on the marked price he makes 10% profit but after allowing 2x% discount on the marked price he makes 40% loss. What is the marked price of the toy?

A motorboat takes x hours to travel 900 km in downstream and it takes y hours to travel the same distance in upstream. If the speed of the stream is 2 km per hour and the speed of the motorboat in still water is 8 km more than the speed of the stream, then find the sum of x and y?

When A and B work together then they take 4 hours to complete a piece of work. When B alone works at 75% of his efficiency then he takes 8 hours to complete half of the piece of work. Find the number of hours A alone will take to complete the piece of work if he works at 75% his efficiency?

A number is drawn at random from first 100 natural numbers. What is the probability that the number is not a prime number?

A motorboat goes some distance downstream in 2x hours but it returns only 75% of the previous distance in 1.75x hours. What is the ratio of the speed of the motorboat in still water to the speed of stream?

A and B together invested in a business in the ratio of 5 : x respectively. At the end of 6 months, B withdraws 25% of his initial investment but at the end of 1 year, B’s share in profit was 40% more than that of A. What was the value of x?

Two persons A and B working together can complete a piece of work in 15 days but a third person C can destroy half the completed work in 15 days. In how many days A, B, and C working together can complete one fourth of the piece of work?