A man goes from A to B at a speed of 21 kmph and comes back to A at a speed of 21 kmph. Find his average speed for the entire journey?  Choose one
A) 23.3 kmph
B) 25.3 kmph
C) 22.5 kmph
D) 22.3 kmph
E) 22.9 kmph
Distance from A and B be 'd'   Average Speed = total distance/total time   Average Speed = (2d)/[(d/21) + (d/24]   = (2d)/[15d/168) =&gt; 22.3 kmph.   Answer:22.3 kmph
<result>D</result>
A man goes from A to B at a speed of 21 kmph and comes back to A at a speed of 21 kmph. Find his average speed for the entire journey?