A weight of 1000 grams hangs from a lever 20cm to the fulcrum. At the left is a 500-gram weight 20cm from the fulcrum, and a 200-gram weight x cm away from the fulcrum. What is the value of x that will make the lever balanced?
50cm
20cm
10cm
30cm
70cm
Correct answer is D
Taking moment about F,
200(X + 20) + (500 x 20) = (1000 x 20)
200X + 4000 + 10000 = 20000
200X + 14000 = 20000
200X = 20000 - 14000
200X = 6000
X = 30cm