MathDB

There are

30

apparently equal balls,

15

of which have the weight

a

and the remaining

15

have the weight

b

with

a \ne b

. The balls are to be partitioned into two groups of

15

, according to their weight. An assistant partitioned them into two groups, and we wish to check if this partition is correct. How can we check that with as few weighings as possible?

Problem Statement