Question

Nine different letters are to be dropped in three different letter boxes. In how many different ways can this be done?  

(a) 27 (b) 3⁹ (c) 9² (d) 3⁹ –3

Answer 1

(b) First letter can be dropped into any of the 3 boxes. It can be done in 3 ways. Similarly second letter can also be dropped into any of the 3 boxes in 3 ways and so on. Hence, total no of ways = 3×3×3×.........upto 9 times = 3⁹