Jack sailed his boat 128 km down a river in the same time it took to travel 112 km up the river.His speed down

Question

stream was 4 km/h more than he averaged upstream.What was his speed traveling down the river?
topic is:Solving Motion problems.Hope yo could help me.thanx

Answer 1

128 / ( x + 4 ) = 112 / x
128 x = 112 ( x + 4 ) = 112 x + 448
16 x = 448
x = 28 km/hr upriver and x + 4 = 32 km/hr downriver