Problema Solution
a boat's crew rowed 12 miles downstream, with the current, in 1.5 hours. the return trip upstream, against the current, covered the same distance, but took 4 hours. find the crew's rowing rate in still water and the rate of the current.
Answer provided by our tutors
let
x = the crew's rowing rate
c = the rate of the current
d = 12 miles
d/(x + c) = 1.5
d/(x - c) = 4
or
12/(x + c) = 1.5
12/(x - c) = 4
by solving the system of equations above we find
x = 5.5 miles/hour
c = 2.5 miles/hour
the rowing rate in still water is 5.5 miles/hour.
the rate of the current is 2.5 miles/hour.