Question

Susan drove to visit a friend. She drove 345

miles in 5 hours and 45 minutes. What was her

average speed, to the nearest tenth of a mile per

hour?

Answer 1

`Average\ Speed = 60 mi/hr`

Explanation:

Given

`Distance = 345\ miles`

`Time = 5\ hours\ 45\ minutes`

Required

Determine the average speed

This is calculated as thus:

`Average\ Speed = (Distance)/(Time)`

Convert time to hour:

`Time = 5\ hours\ 45\ minutes`

`Time = 5\ hours + (45)/(60)\ hour`

`Time = 5\ hours + (3)/(4)\ hour`

`Time = (20 + 3)/(4)\ hours`

`Time = (23)/(4)\ hours`

`Time = 5.75\ hours`

`Average\ Speed = (Distance)/(Time)`

`Average\ Speed = (345)/(5.75)`

`Average\ Speed = 60 mi/hr`