Fidelity Investments Interview Question: You have 8 balls, one being s... | Glassdoor

Interview Question

LEAP Program Interview

You have 8 balls, one being slightly heavier than the rest

 . You have a balance and you can only use it twice, how do you single it out?

Interview Answer

3 Answers


weigh 3 balls on each side of the scale. if they balance, one of the two off the scale is your ball. If the sides don't balance, take the 3 balls from the heavy side and put 2 of them on opposing sides of the scale, the heavy side will give you your answer. However if they balance, the one you left off the scale on the second weighing is the heaviest ball.

mark on Feb 21, 2011

Weigh four balls on each side. Now split and weigh the balls on the heavy side two against two. Take the 2 balls on the heavy side and lay a straight edge across the top. The larger ball is heavier.

Peter on Feb 22, 2011

an87 on Jun 13, 2011

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