Question

A salesman drove from his home to a nearby city at an average speed of 40 mi/h. He returned home at an average speed of 50 mi/h. What was his average speed for the entire trip?

Answer 1

44.44 mph

Explanation:

`speed = (distance)/(time) = (distanceTo + distanceFrom)/(time1 + time2) = (2d)/((d)/(40) + (d)/(50) )`

=
`(2d)/((5d + 4d)/(200) ) = (2d)/((9d)/(200) )`

= 2d *
`(200)/(9d)`

= 400 / 9

= 44.44

Answer 2

44.4 miles per hour

Explanation:

d = the distance between cities

t 1= the time from home to the city

t 1 = the time . from the city to home

2d/t1 + t2 = 2d/ d/40 + d/50

=2d/5d+4d =2d/9d

divide both sides by 200

=2d * 200/9d =400/9

= 44.4