Question

Two persons enter a railway compartment where there are 6 vacant seats. In how many different ways can they seat themselves? 

(a) 36 

(b) 11 

(c) 30 

(d) 12

Answer 1

(c) 30

The first person can sit on any of the six vacant seats. 

∴ Number of ways to seat first person = 6 

Now the second person can sit on any of the remaining five seats. 

So number of ways to seat second person = 5 

∴ Total number of ways in which both can be seated = 6 × 5 = 30.