The current of a stream runs at the rate of 4 kmph.

The current of a stream runs at the rate of 4 kmph. A boat goes 12 km and back to the starting point in 2 hours, then find the speed of the boat in still water?

Quiz

Answer/Solution

E)13.21

Steps/Work

S = 4
M = x
DS = x + 4
US = x - 4
12/(x + 4) + 12/(x - 4) = 2
x = 13.21
Answer:E