Question

Rina drove for 1 hour at 45 mph and 1.5 hours at 50 mph. What was her average speed for the trip?

Answer 1

1hour at 45mph , total distance = 45miles
1.5hours at 50kmph , total distance= 50 × 1.5 = 75miles

total distance tracaled = 120mls
total time = 2.5 hours


`(miles)/(hour) = (120)/(2.5) = 48mph`

Answer 2

Her average speed for the trip was 48 mph.

Explanation:

Rina drove 1 hour at the speed = 45 mph

Distance covered in 1 hour = 45 miles

she drove 1.5 hours at the speed = 50 mph

Distance covered in 1.5 hour = 50 × 1.5 = 75 miles

Total distance covered by Rina = 45 + 75 = 120 miles

Total time taken by Rina = 1 + 1.5 = 2.5 hours

Average speed = Total distance / Total time

= 120 ÷ 2.5 = 48 mph

Her average speed for the trip was 48 mph.