Question

Leah drives 45 miles per hour for 2 hours then 32 miles per hour for 90 minutes . What is her average speed

Answer 1

average speed =
`(total distance)/(total time)`

45 mph for 2 hours to distance = 45miles x 2 hours = 90 miles

convert 90 minutes to hours:
`(90 minutes)/(60 minutes) × 1 hour =1.5 hours`

32 mph for 1.5 hours = 48 miles

average speed =
`(90+48 miles)/(2+1.5 hours) = 39.429 miles/hour`

Answer 2

=39.42857143 miles per hour

Explanation:

To find the average speed, we need to the total distance and the total time

Distance 1

45 miles for 2 hours

45*2 = 90 miles

Distance 2

90 minutes * 1 hour/60 minutes = 1.5 hours

32 miles * 1.5 hours =48 miles

The total distance = 90+48 = 138 miles

The total time = 2 +1.5 = 3.5 hour

The average speed = total distance/ total time

= 138/3.5

=39.42857143 miles per hour