Maxwell leaves his home and walks toward Brad's house at the same time that Brad leaves his home and runs toward Maxwell's house. If the distance between their homes is 50 kilometers, Maxwell's walking speed is 4 km/h, and Brad's running speed is 6 km/h. What is the distance traveled by Maxwell when they meet in the middle? Choose the correct choice from the following answers.
A) 16 B) 18 C) 20 D) 24 E) 30

Rationale: "distance between maxwell ' s and brad ' s home = 50 km maxwell ' s speed = 4 km / h brad ' s speed = 6 km / h relative speed of approach = 10 km / h time = 50 / 10 = 5 hours distance traveled by maxwell when they meet in the middle = 4 * 5 = 20 km answer c"
Answer: C