Problema Solution
A boy rows 6 miles downstream in 64 minutes. He rows back at the same rate in 180 minutes. Find the rate of the stream and the boy's rate in still water.
Answer provided by our tutors
Downstream DATA
time = 64 minutes ; distance = 6 miles ; rate = d/t = 6/64 miles per minute
Upstream DATA:
time = 180 minutes ; distance = 6 miles ; rate = d/t = 6/108 miles per minute
b + c = 6/64
b - c = 6/108
Combine the equations
2b = 6/64 + 6/108
b = 3/64 + 3/108
b = 0.07465 miles per minute
b = 4.48 miles per hour (speed of the boy in still water)