Natasha rides her bike (at a constant speed) for 5 hours, helped by a wind of 2 miles per hour. Pedaling at the same rate, the trip back against the wind takes 9 hours. Find find the total round trip distance she traveled.

Question

anonymous · Answer

Let x be the speed of the bike in no wind.
r*t=d
Solve the following for x:
(x + 2) 5 = 9 (x - 2)
x=7 mph
Using the LHS of (x + 2) 5 = 9 (x - 2) evaluated at x=7.
(7 + 2) 5=45miles
The round trip distance is 2*45 = 90 miles.