A person travels from P to Q at a speed of 40 kmph and returns by increasing his speed by 50%. What is the average speed for both the trips?

A 36kmph

B 45 kmph

C 48 kmph

D 50 kmph

Correct Answer: Option C

Speed while going = 40 km/hr Speed while returning = 150% of 40 = 60 km/hr

Average speed = 2xy/(x+y)

= 2*40*60/(40+60)

= 4800/100 = 48 kmph