John took a bus from home to market, that travels at 50 kmph. While walking back at 5 kmph,
halfway through, he suddenly realized he was getting late and he cycled back the remaining distance in 35 kmph. Find the average speed. Choose the correct choice:	A) 8.5 kmph	B) 16.0 kmph	C) 22.5 kmph	D) 18.6 kmph	E) none of these

Rationale: let the distance be 2 x ( one way ) time taken by bus = 2 x / 50 , by walking = x / 5 , by cycling = x / 35 hours : . average speed = total distance / total time = 5 x / x / 25 + x / 5 + x / 35 = 5 * 60 / 2.4 + 12 + 1.7 = 18.6 answer : d
Answer: D