SOLUTION: Joy is riding her bicycle up a hill. After travelling 3km, Joy passes Greg who is walking down the hill at a rate of 1m/s. Joy continues up the hill for another 7km before riding d

Question 998808: Joy is riding her bicycle up a hill. After travelling 3km, Joy passes Greg who is walking down the hill at a rate of 1m/s. Joy continues up the hill for another 7km before riding down the hill double the average speed she went up. Joy ang Greg meet at Joy's starting point at the same moment. In meters per second, what was Joy's average speed going down the hill?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!

Joy rides7 km = 7000 m at x m/s
time up = 7000/x
time down = 10000/2x
Time up + time down for joy = time by greg to reach the starting
7000/x + 10000/2x = 3000
multiply by 2x
14000 +10000 = 2x*3000
24000 = 6000x
x = 4 m/s up the hill
downhill 4*2 = 8 m/s

RELATED QUESTIONS
Joy and Glenn each went on a bike ride. - Joy rode at a rate of 0.05 miles per... (answered by richwmiller)

Johnny rode his bicycle down a hill. It took him 15 seconds to ride from the top of the... (answered by ankor@dixie-net.com)

Marco�s speed riding up a hill is 40% of his speed riding down the hill. It takes him two (answered by ankor@dixie-net.com)

Jane runs up a 3-mile hill at 3mph and down the hill at 6mph. What is her average... (answered by Alan3354)

Johnny rode his bicycle down a hill. It took him 15 seconds to ride from the top of the... (answered by Alan3354)

Hannah is riding her bicycle at 25 meters/second on level ground towards Bagley's Hill.... (answered by ikleyn)

Please help, thanks a bunch A bicyclist is riding in a hilly area. She approaches a... (answered by josmiceli)

Hey how would you set up this equation? Istas rides her bicycle down a hill. For every... (answered by solver91311,MathTherapy)

What is the average speed of a cyclist who bikes up a hill at 6mph but then bikes back... (answered by josmiceli)