Answer:
Step-by-step explanation:
Let x represent the time that they spent biking at the first speed.
If the ride was six hours long, it means that the time they spent biking at the other speed is (6 - x) hours.
Distance = speed × time
For the first part of the ride, they biked at a speed of 7 mph. This means that the distance travelled during the first part of the ride is
7 × x = 7x
For part of the ride, they biked at a speed of 11 mph. This means that the distance travelled during the second part of the ride is
11(6 - x)
Since the total distance that the kids traveled is 54 miles, then
11(6 - x) + 7x = 54
66 - 11x + 7x = 54
11x - 7x = 66 - 54
4x = 12
x = 12/4 = 3
They spent 3 hours biking at the first speed.
They spent 6 - 3 = 3 hours biking at the other speed.
