While driving from A-ville to B-town, Harriet drove at a constant speed of 100 kilometers per hour. Upon arriving in B-town, Harriet immediately turned and drove back to A-ville at a constant speed of 150 kilometers per hour. If the entire trip took 5 hours, how many minutes did it take Harriet to drive from A-ville to B-town? Pick one
A) 138  B) 148  C) 150  D) 162  E) 180

Rationale: "5 hr = 300 min . if harriet spend equal hrs on each leg she will spend 150 min on each . since speed a - b is less than speed b - a and distance on each leg is the same , time spent on a - b is more than 150 min , which mean we can eliminate ans . a , b and c . now let plug in ans . d or e and verify which one give same distance on each leg . e . t = 180 min * leg a - b - - - > d = 100.180 / 60 = 18000 / 60 * leg b - a - - - - > d = 150 * 120 / 60 = 18000 / 60 so the correct ans . ise"
Answer: E