Aptitude Interview Question:

Ten boxes are there. Each ball weighs 100 gms. One ball is weighing 90 gms.
i) If there are 3 balls (n=3) in each box, how many times will it take to find 90 gms ball?
ii) with n=10
iii) with n=9

Submitted by: Administrator

6 Chances.
First keep 5 boxes in each in a balance. Then the one with low weight. Take it divide 5 boxes as 2-2-1.
Keep 2-2 in each of balance. If both weigh same... then take the one left. In which we have 3 balls.
1-1-1
Keep any 2 balls in balance. If both weigh the same. The one left is of low weight..!
Else if both don't weigh the same then the one with low weight is the one req. as such is for n 10.
Submitted by: Administrator