A hiker walking at a constant rate of 4 kilometers per hour is passed by a cyclist travelling in the same direction along the same path at a constant rate of 18 kilometers per hour. The cyclist stops and waits for the hiker 5 minutes after passing her while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?	Pick one:
A) 7.5 B) 12.5 C) 17.5 D) 22.5 E) 27.5

Rationale: in 5 minutes , the cyclist travels a distance of ( 5 / 60 ) * 18 = 1.5 km . the time it takes the hiker to complete this distance is 1.5 / 4 hours = 22.5 minutes the cyclist needs to wait 22.5 - 5 = 17.5 minutes the answer is c .
Answer: C