Question

There are four different routes between city S and city T. How many ways can a round trip be made from S to T and back if it is desired to take a different route on the way back?

A. 12
B. 7
C. 8
D. 16

Answer 1

To find the number of ways a round trip can be made from city S to city T and back, taking a different route on the way back, we consider the number of routes for each leg of the trip. With four different routes, there are 4 options for the outbound route and 3 remaining routes for the return trip, resulting in 12 possible round trip combinations.

Step-by-step explanation:

To find the number of ways a round trip can be made from city S to city T and back, taking a different route on the way back, we need to consider the number of routes for each leg of the trip. Since there are four different routes between S and T, there are 4 options for the route from S to T, and for each of those options, there are 3 remaining routes to choose from for the return trip (since a different route is desired). So, the total number of ways to make a round trip is 4 multiplied by 3, which equals 12. Therefore, the answer is A. 12.