Question

In how many ways can 4 letters be posted in 5 letter boxes?

Answer 1

Given: We have 4 letters and 5 letter boxes 

To Find: Number of ways of posting letters. 

One letter can be posted in any of 5 letter boxes. 

We have to assume that all the letters are different. 

So for first letter i.e. L₁, we have 5 ways 

Similarly for,

L₂ = 5 way

L₃ = 5 way

L₄ = 5 way

Total number of ways = 5 × 5 × 5 × 5 = 625 

In 625 ways 4 letters can be posted in 5 letter boxes