Xavier starts from P towards Q at a speed of 40 kmph and after every 12 mins increases his speed by 20 kmph. If the distance between P and Q is 56 km, then how much time does he take to cover the distance?
Select: A) 40 B) 48 C) 44 D) 36 E) 30

Rationale: "first 12 min = 40 * 12 / 60 = 8 km 2 nd 12 min = 60 * 12 / 60 = 12 km 3 rd 12 min = 80 * 12 / 60 = 16 km 4 th 12 min = 100 * 12 / 60 = 20 km total time 12.4 = 48 min b"
Answer: B