Two Balls

Ganesh, a brilliant student is now at a situation which decides his future life. He is facing the last question of a final round of technical interview of Microsoft. If he clears this question, he would be selected by Microsoft and his life would change. The question goes this way. “There is a building with 7643 floors. You are given two plastic balls. A threshold floor is the one from and above which when a given ball is dropped, the ball breaks and below which when the ball is dropped, the ball doesn’t break. Your aim is find the minimum number of drops required to find the threshold floor.” Ganesh finally solved the problem and got selected for Microsoft.

How would you do that?