A man goes from A to B at a speed of 15 kmph and comes back to A at a speed of 12 kmph. Find his average speed for the entire journey? Pick one:
A) 13.7 kmph	B) 13.3 kmph	C) 13.8 kmph	D) 13.9 kmph	E) 12.3 kmph

Rationale: distance from a and b be ' d ' average speed = total distance / total time average speed = ( 2 d ) / [ ( d / 15 ) + ( d / 12 ] = ( 2 d ) / [ 9 d / 60 ) = > 13.3 kmph . answer : b
Answer: B