You have 4 weights weighing 2,3,5 and 7 pounds. The problem is none of them are marked. What is the fewest number of weighings you need using a balance scale figure out which weights are which?
1. weigh all 4 weights>> a+b+c+d=w
2 take out one weight and weigh the other 3>>a+b+c=x
3 take out one more weight and weigh the other 2>>a+b=y
4 take out one more weight and weigh the last one>>a=z
on solving equation 1,2,3,4 to figure out the weights
therefore fewest number of weighings you need = 4
fewest numbers = 4
