SOLUTION: Mary rides her bicycle to her friend Amy's house and returns home by the same route. Mary rides her bike at constant speeds of 6mph on level ground, 4mph when going uphill and 12m

Algebra.Com
Question 76682: Mary rides her bicycle to her friend Amy's house and returns home by the same route. Mary rides her bike at constant speeds of 6mph on level ground, 4mph when going uphill and 12mph when going downhill. If her total riding time was 2 hours, how far is it to Amy's house?
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
Mary rides her bicycle to her friend Amy's house and returns home by the same route. Mary rides her bike at constant speeds of 6 mph on level ground, 4 mph when going uphill and 12 mph when going downhill. If her total riding time was 2 hours, how far is it to Amy's house?
:
Let x = distance one way distance on level ground
Let d = distance from Mary to Amy's house
Then hill dist = (d-x)
:
Write a time equation; Time = distance/speed:
:
level time + uphill time + downhill time + level time = 2hr
+ + + = 2
Multiply equation by 12
2x + 3(d-x) + (d-x) + 2x = 12(2)
:
4x + 3d - 3x + d - x = 24
:
4x - 3x - x + 3d + d = 24
:
4d = 24
d = 24/4
d = 6 mi from Mary to Amy's house
:


RELATED QUESTIONS

Marlene rides her bicycle to her friend jhon's house and returns homeboy the same route.... (answered by ankor@dixie-net.com)
Mary rides her bike to john's house, she returns the same way. She rides at a constant... (answered by solver91311)
SOLVE: ERIN RIDES HER BIKE AT A CONSTANT SPEED FOR 21 MILES. SHE THEN RETURNS HOME AT (answered by stanbon)
Mary visits her friend Annie and then returns home by the same route. She walks 2km/h... (answered by KMST)
Mary lives 6 miles from the mall. She rides her bike to the mall. She rides 4 miles... (answered by ankor@dixie-net.com)
Can you please help me figure this problem out and show the work so I can understand what (answered by venugopalramana)
Debbie rides her bicycle to her friends' house. Debbie rides her bike 4mph when going... (answered by ikleyn,Alan3354,greenestamps)
Lois rides her bike to visit a friend. She travels at 10 mi/h. While she's there, it... (answered by richwmiller)
Adam leaves school at 4 p.m. and walks home at a constant pace of three mph. Amy leaves... (answered by solver91311)