# Ball in the box

**Logic**Level 3

There are 10 boxes, of 10 balls in each of the box. Each ball weigh \(10\text{ g}\). Now for instance, *Any one of the box is replaced with another box, of each 10 balls, where each ball weigh \(9\text{ g}\) instead*. You have one electronic machine.

Find out how many number of trails you need to find which box contains \(9\text{ g}\) balls.

**Clarifications**:

Taking a box is counted as a trail (eg. taking 2 boxes means 2 trails)

Taking balls from any boxes is counted as a trail (eg. taking 1 ball from first box, 5 balls from last box means 1 trail only)