Math middle school

Question

You row a canoe X miles per hour down a river for 20 minutes. On the return trip, you travel 1 mile per hour slower. The return trip takes 30 minutes. How far did you ride the canoe in total?

Answer 1

d/x = 1/3, d/(x - 1) = 1/2

Fro first equation x = 3d, d/(3d - 1) = 1/2. from here 3 d - 1 = 2d, d = 1, 2d = 2 mi