The ratio of sand to gravel in a mixture is 3 : 4, while that between gravel and cement is 6 : 7. What is the ratio of sand to cement in the mixture?

The ratio of sand to gravel in a mixture is 3 : 4, while that between

1.	The ratio of sand to gravel in a mixture is 3 : 4, while that between gravel and cement is 6 : 7. What is the ratio of sand to cement in the mixture?
A.	8 : 11
B.	3 : 5
C.	49 : 59
D.	9 : 14
Answer» E.