A kayaker travels X miles per hour down stream for three hours. On the for our return trip, the kayak or travels 1 mph slower. How far did the kayak or travel in total?

3x is the miles from downstream

4 (x - 1) is the return trip

Solution:

3x = 4 (x - 1)

3x = 4x - 4

-x = - 4

x = 4

The outward journey 3x = 12 miles

Return journey is same length

Therefore the distance travel is 24 miles