You are given four balloons: red, blue, green and yellow. Some (or all) of the balloons might be counterfeit.
A detector box can display the quantity of counterfeit balloons inside the box.
Your task is to detect all the genuine balloons using the detector box not over three times.
How would you do it?
Source: Russian Kvantik.
(In reply to Solution
Jer, I believe your set of tests (+ its
permutations) is the only one providing different answers for all
subsets of (A,B,C,D).
I’ve initially tried AB,AC,AD but it does not distinguish between A and BCD, -
i.e. (1,1,1) in both cases.