A man goes from A to B at a speed of 20 kmph and comes back to A at a speed of 30 kmph. Find his average speed for the entire journey?  Pick
A) 20 kmph B) 24 kmph C) 50 kmph D) 35 kmph E) 30 kmph
Explanation:   Distance from A and B be 'd'   Average Speed = total distance/total time   Average Speed = (2d)/[(d/20) + (d/30)]   = (2d)/[5d/60) =&gt; 24 kmph.   ANSWER IS 24 kmph
<result>B</result>
A man goes from A to B at a speed of 20 kmph and comes back to A at a speed of 30 kmph. Find his average speed for the entire journey?