Question

Assuming that in San Salvador there are only ten buses that run between San Salvador and Zacatecoluca. Under those conditions, how many ways could a person travel from San Salvador to San Vicente and return on a different bus?

a) 9
b) 10
c) 19
d) 90

Answer 1

Given ten buses, a person can travel from San Salvador to San Vicente and return on a different bus in 90 different ways by multiplying 10 choices for the outbound trip by 9 choices for the return trip.

Step-by-step explanation:

The question asks how many different ways a person can travel from San Salvador to San Vicente and return on a different bus, given that there are only ten buses that operate between these locations. When the person travels to San Vicente, they can choose from any of the ten buses. However, for the return trip, they must choose a different bus, which means there are only nine buses available for selection. Therefore, the number of different ways to make the round trip is the product of the number of choices for each leg of the trip.

For the outbound trip, they have 10 choices, and for the return trip, they have 9 choices. By multiplying these numbers together, we get:

10 choices for the first trip × 9 choices for the return trip = 90 different ways.