Interview Question

Interview

You are given nine balls, one of which weighs less than the

  rest. You are also given a traditional two-sided scale. How many times do you need to weigh balls to determine which is the lightest one?
Answer

Interview Answer

1 Answer

1

2 weighings Seperate balls into 3 groups of 3. Put a group of 3 on each 1/2 of the scale. If the scale balances, the the light ball is in the 3rd group. If they don't balance, then you know the ball is in the 'light' group. Clear the scales and put one ball from the light group on each side of the scales. If the balance, then it's the 3rd ball.

JG on Jan 17, 2013

Add Answers or Comments

To comment on this, Sign In or Sign Up.