Question

Getting at 8:30 a.m. Tours of the National Capital and the White House begin at a tour agency. Tours for the National Capital leave every 15 minutes, and tours for the White House leave every 20 minutes. How often do the tours leave at the same time?

a) Every 5 minutes
b) Every 10 minutes
c) Every 15 minutes
d) Every 20 minutes

Answer 1

The tours for the National Capital and the White House leave at the same time every 60 minutes.

Step-by-step explanation:

The tours for the National Capital and the White House leave at the same time when their departure schedules coincide. To find the frequency of when the tours leave at the same time, we need to determine the least common multiple (LCM) of the tour intervals.

The tour for the National Capital leaves every 15 minutes, while the tour for the White House leaves every 20 minutes. The LCM of 15 and 20 is 60. This means that the tours will leave at the same time every 60 minutes.

Therefore, the tours leave at the same time every 60 minutes.