There are three stations A,B and C five routes for going from station A to station B and four routes for going from station B to station C. find number of different ways through which a person can go from A to C via B.

Explanation

Since, there are five routes for going from A to B. so, there are four routes for going from to C.

Hence, by the fundamental principal of multiplication, total number of different ways
`=5xx4` [i.e., A to B and then B to C]
`=20` ways