The strength of a joint in a bolted connection is 620 kN. The size of plate is 180 mm width and 20 mm thick. If the yield strength of material of plate as 250 N/mm2 and partial safety factor as 1.1, then the efficiency of the joint is ______.

The strength of a joint in a bolted connection is 620 kN. The size of

1.	The strength of a joint in a bolted connection is 620 kN. The size of plate is 180 mm width and 20 mm thick. If the yield strength of material of plate as 250 N/mm2 and partial safety factor as 1.1, then the efficiency of the joint is ______.
A.	90%
B.	63.67%
C.	75.75%
D.	65.75%
Answer» D. 65.75%