Question

A jet plane traveling at 450 mph overtakes a propeller plane traveling at 250 mph that had a 3​-hour head start. How far from the starting point are the​ planes?

Answer 1

it's suppose to add 450mph+250mph=700 then divide 3 hours=233.3

Answer 2

1687.5 miles

Explanation:

Given: A jet plane traveling at 450 mph overtakes a propeller plane traveling at 250 mph that had a 3​-hour head start.

To Find: How far from the starting point are the​ planes

Solution:

Speed of jet plane =
`450`
`\text{mph}`

speed of Propeller plane =
`250`
`\text{mph}`

Distance travelled by propeller plane in 3 hours head start =
`\text{speed of propeller plane}*\text{time}`

=
`250*3` =
`750`
`\text{miles}`

Distance to be travelled by jet plane to overtake propeller plane =
`\text{distance between both planes}`

`750`
`\text{miles}`

Relative speed of both planes =
`\text{Speed of jet plane}-\text{speed of propeller plane}`

`450-250=200`
`\text{mph}`

Time taken by jet plane to overtake propeller plane =

`\frac{\text{Distance between both planes}}{\text{relative speeds of planes}}`

`(750)/(200)=(15)/(4)`
`\text{hours}`

total distance travelled by plane =
`\text{Time taken by jet plane to overtake propeller plane}*\text{speed of jet plane }`

`450*(15)/(4)=1687.5`
`\text{miles}`

planes are
`1687.5`
`\text{miles}` far from starting point.