Question

A boat leaves Astoria and travels upstream on the Columbia river for 5 hours. The return trip only takes 3.6 hours because the boat travels 4 miles per hour faster downstream due to the current. How far does the boat travel up the Columbia? Suppossed to solve as an in equality?

Answer 1

10.285 miles

Explanation:

Given that:

Upstream travel time = 5 hours

Return trip travel time = 3.6 hours

Let upstream travel speed = x mph

Downstream travel speed = x + 4 mph

Distance = speed * time

Upstream distance = x * 5 = 5x

Downstream distance = (x + 4) * 3.6

5x = (x + 4) * 3.6

5x = 3.6x + 14.4

5x - 3.6x = 14.4

1.4x = 14.4

x = 10.285714

x = 10.285 miles