Question

A rowing team rowed 60 miles while going with the current in the same amount of time as it took to row 30 miles going against the current. The rate of the current was 3 miles per hour. Find the rate of the rowing team in still water.

Rate of the team in still water: miles/hours

Answer 1

9 miles/hour

Explanation:

The relation between time, speed, and distance can be used to write an equation for the team's rowing speed.

Setup

Let s represent the team's rowing speed in still water. Then the downstream speed is (s+3) and the upstream speed is (s-3). The travel times over the given distances are the same, so we have ...

time = distance/speed

60/(s+3) = 30/(s-3)

Solution

Multiplying by (s-3)(s+3)/30, we have ...

2(s -3) = (s +3)

s = 9 . . . . . . . . . add 6-s to both sides

The team's rowing speed in still water is 9 miles per hour.