IKMC 2027 - Grades 7-8 - Self-study SET 3 - Thematic Batch 3 Question 22

Jess and Mo run together. Jess runs at 10 miles per hour and Mo at 8 miles per hour. After every mile, Jess stops and waits for Mo to catch up. After 20 miles, how many minutes has Jess spent waiting?

Editorial note: Include the wait for Mo at the 20-mile finish marker.