You have 10 boxes of balls (each ball weighing exactly10 gm) with one box with defective balls (each one of the defective balls weigh 9 gm). You are given an electronic weighing machine and only one chance at it. How will find out which box has the defective balls?
Keep the first box and observe the weight
Keep the second box over it. now note the wieght
If the weight is multiplied twice exactly, then continue the same process
(if that doesn't happen , then it is the odd box)
keep the third box and check whether the first weight is multiplied thrice
Continue the same process
