Aroller coaster holds up to 6 people per ride . there are 15 adult and 9 children standing in line . how many times will the roller coaster need to be run for everyone standing in line to have a ride?

The roller coaster will need to run 4 times.

Explanation:
If there are 15 adults and 9 children, then we know that they're 24 people in total on the line (15 + 9 = 24). Now, we divide 24 by 6, because there are 24 people and a roller coaster holds up to 6 people. 24/6 = 4, therefore the roller coaster will need to run 4 times.

Add the people in line.
15 + 9 = 24
Divide the total number of people by 6 since 6 can ride each time.
24/6 = 4
It needs to run 4 times for everyone in line to have a ride.