Marla starts running around a circular track at the same time Nick starts walking around the same circular track. Marla completes 10 laps around the track per hour and Nick completes 5 laps around the track per hour. How many minutes after Marla and Nick begin moving will Marla have completed 4 more laps around the track than Nick? Choose the correct choice from the following choices.
A) 5 B) 48 C) 12 D) 15 E) 20

Rationale: maria ' s rate - 10 laps per hour - - > 10 / 60 laps / min nick ' s rate - 5 laps per hour - - > 5 / 60 laps / min lets set equations : 10 / 60 * t = 4 ( since maria had to run 4 laps before nick would start ) 5 / 60 * t = 0 ( hick has just started and has n ' t run any lap yet ) ( 10 / 60 - 5 / 60 ) * t = 4 - 0 ( since nick was chasing maria ) t = 48 min needed maria to run 4 laps answer : b
Answer: B