Interview Question

Product Support Specialist Interview

-Leeds, England, England


You have 3 bags of marbles; one filled with Red marbles, one with green, and the third containing a mixture of the two. They are all labelled with either Red/Green/Mixed, except all the labels are wrong. How many marbles would you need to take out to determine what marbles are in each bag, and why?


Interview Answers

2 Answers


One Marble. All you know about the bags are that every label is wrong, which would mean that the bag labelled "Mixed" must actually only contain either Red or Green marbles. So by taking a marble out of the bag, say if its Red, you can determine the contents of the other two bags. So the one labelled mixed is actually Red. The bag labelled Red must either be Green or Mixed, and the bag labelled Green must either be Red or Mixed. We have already determined where the red marbles are, so the bag labeled green must be the mixed marbles, leaving the final bag (labelled red), to actually be green.

Anonymous on


they are only assumptions@

Anonymous on

Add Answers or Comments

To comment on this, Sign In or Sign Up.