In the following diagram, the counter-clockwise torque is equal to

10 nm
80 nm
400 nm
500 nm

400 Nm

Explanation:

Moments are given by multiplying force and distance

Taking moments where the pivot is locate

The counter-clockwise moment is given by 100*5= 500 Nm (It moves against the normal direction of the clock considering the pivot location)

Clockwise moments is given by 40*2= 80 Nm (Moment moves in the direction of clock considering pivot location)

i don't know, you need to give me some answers.

explanation:

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.