Jake took a bus from home to market, that travels at 10 kmph. While walking back at 2 kmph,
halfway through, he suddenly realized he was getting late and he cycled back the remaining distance in 50 kmph. Find the average speed.  Pick
A) 1.17 kmph B) 1.67 kmph C) 0.69 kmph D) 1.45 kmph E) none of these

Rationale: let the distance be 2 x ( one way ) time taken by bus = 2 x / 10 , by walking = x / 2 , by cycling = x / 50 hours : . average speed = total distance / total time = 2 x / x / 5 + x / 2 + x / 50 = 2 * 60 / 12 + 30 + 1.2 = 1.67 answer : b
Answer: B