A boy is travelling from his home to school at 5 km/hr and reached 7 min late. Next day he traveled at 10 km/hr and reached 8 min early. Distance between home and school?	Choose the correct choice from the following answers:
A) 2.5 km
B) 3.5 km
C) 4.5 km
D) 5.5 km
E) 6.5 km

Rationale: let the distance be x t 1 = x / 5 hr t 2 = x / 10 hr difference in time = 7 + 8 = 15 = 1 / 4 hr x / 5 - x / 10 = 1 / 4 x / 10 = 1 / 4 x = 2.5 km answer is a
Answer: A