SOLUTION: A cyclist rides 600 meters up a hill and 400 meters down the other side. his speed is twice as fast downhill as uphill and the whhole journey takes 4 minutes. how long does it take

Question 573698: A cyclist rides 600 meters up a hill and 400 meters down the other side. his speed is twice as fast downhill as uphill and the whhole journey takes 4 minutes. how long does it take him to reach the summit?
My working out
Distance over time= speed so the total journey is 1000 meters and the total time is 4 minutes(240 seconds)
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = his speed going uphill ( m/min )
= his speed going downhill ( m/min )
Let = His time going up hill ( min )
= his time going downhill ( min )
--------------------------------
uphill:
(1)
downhill:
(2)
-------------------
(1)
Substitute (1) into (2)
(2)
(2)
(2)
(2)
(2)
(2)
It takes him 3 minutes to reach the summit
check:
(1)
(1)
(1)
and
(2)
(2)
(2)
OK
RELATED QUESTIONS
A bicyclist rides his bicycle 20 miles up a hill and then comes back down. His speed... (answered by jorel1380)

A bicyclist rides his bicycle 12 miles up a hill and then comes back down. His speed... (answered by ikleyn)

Matt rides his bicycle 12 miles up a hill and then 16 miles on level terrain. His speed... (answered by josgarithmetic)

Tina rides her bike 15m up a hill and then 15m. down the same hill. This complete trip... (answered by Alan3354)

Really stumped on this one!!! A bike is rode 15 miles up a hill and then 15 miles back (answered by josmiceli)

A cyclist rides over a hill , a total journey of 9km. His average speed uphill is 8km/hr... (answered by ikleyn)

Freddie gets a car ride to the top of a hill, then rides his skateboard back down. The... (answered by richwmiller,stanbon)

Peter cycles at 4 mph uphill, and 12 mph downhill. He rides from his house at the bottom... (answered by Alan3354)

My daughters math problems are making me crazy, hope you can help me so I can help her. (answered by stanbon)