# 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)

×