Goldman Sachs Interview Question: Given 9 ball with only one di... | Glassdoor

## Interview Question

Analyst/Developer Interview London, England (UK)

# Given 9 ball with only one differ in weight, how to find

out by measuring them only twice?

7

Take 3 balls each. Weigh by keeping 3 on one side and three on other and keep the remaining 3 aside.

1. If the weigh comes as equal u know the ball with diff in weight is in the three kept aside. So again weigh by keeping one of the three on one side and one on other .
If equal the third one is the one that differs in weight else ur weighing machine will tell u the one which differs in weight.

2. If initial weighing is not equal follow step one for the weigh which shows the diff

prachi on Jul 19, 2011
1

Drop them from a sufficient height. If 8 balls land first your 9th is the lightest, if 1 lands first, it's heavier than rest. 1 go, do I get brownie points?

CP on Mar 1, 2012
5

The above is so stupid...even Galileo knew that couldn't happen...and that was over 300 years ago...

wow so so stupid... on Mar 9, 2013
0

In theory, if you do the experiment in air, it is possible.

haha on Sep 12, 2013