Q. A, B and C are three places such that there are three different roads from A to B, four different roads from B to C and three different roads from A to C. In how many different ways can one travel from A to C using these roads?

Explanation : 

A B C are three places

One can travel from A to C in 15 different ways. There are two possible routes: directly from A to C or from A to B and then from B to C.

The number of ways to travel directly from A to C is 3 (since there are 3 different roads). The number of ways to travel from A to B and then from B to C is the product of the number of roads between each pair of places: 3 x 4 = 12.

So, in total, there are 3 + 12 = 15 different ways one can travel from A to C using these roads.