Question

You ride your bike at an average of 12 miles per hour on the way to school, and at an average of 15 miles per hour on the way home. The total ride time is 22 minutes. How far away is school? Round your answer to the nearest hundredth of a mile

im confused....
oobleck
since time = distance/speed, if the distance is d miles, then
d/12 + d/15 = 22/60
first name
thx u so much!