QUANT QUIZ (Arithmetic) FOR SSC CHSL EXAM

Q1. A boy walking at a speed of 10 km/h reaches his school 12 min late. Next time at a speed of 15 km/h reaches his school 7 min late. Find the distance of his school from his house?  
(a)2.5km
(b)5km
(c)3km
(d)6km