Question

A boat traveled 280 miles downstream and back. The trip downstream took 7 hours. Trip back took 14 hours. What is the speed of the boat in still water?

Answer 1

Speed of the boat = u
speed of the current = v

In downstream,
u - v = 280/7
u - v = 40

In upstream,
u + v = 280/14
u + v = 20

Add both equations
2u = 60
u = 30

v = -10

Speed of the boat = 30 km/h