Question

A boat can travel 40mph in still water. If it travels 126 miles with the current in the same length of time it travels 114 miles against the current, what is the speed of the current?
no links please

Answer 1

Answer:

rate of the current = 2 mph

Step-by-step explanation:

d = rt

Let c = rate of the current

Rate going downstream = c + 40

Time going downstream = 126/(40 + c)

Rate going up stream =  40 - c

Time going upstream = 114/(40 - c)

Since the times are equal, then

126/(40 + c) = 114/(40 - c)

126(40 - c) = 114(40 + c)

5040 - 126c = 4560 + 114c

   240c  =  480

          c = 2 mph