## Balancing Scales

#### Problem

In order for the scales to balance the block on the right side must be 10 kg.

It is possible to use the same weights to weigh, for example, 4 kg.

In fact using 2 kg, 3 kg and 5 kg weights it is possible to weigh all but one value from 1 kg to 10 kg. What is that value?

(Note: You don't have to use all three weights.)

Problem ID: 91 (Dec 2002) Difficulty: 1 Star