Interview Question

Machine Learning Scientist Interview



How do you weight 9 marbles three times on a balance scale to select the heaviest one.

AnswerAdd Tags

Interview Answers

3 Answers


Do they all have the same weight except for one?

Paolo on


I think the question is the rest of the 8 balls are the same weight. In that case you can find the heaviest in 2 tries.

Xiaoshu Liu on


First weight 4 vs 4. If they're the same => the last one is the haviest. If not, weight 2 vs 2 of the haviest 4. Then weights 1 vs 1 of the haviest 2.

Aaron on

Add Answers or Comments

To comment on this, Sign In or Sign Up.