Find avrg speed if a man travels at speed of 32km/hr up and 48km/hr dawn at an altitude of 230m. Choose the correct choice from the following answers.
A) 25.8  B) 26.8  C) 38.4  D) 34.4  E) 29.8

Rationale: "avg speed = 2 * x * y / ( x + y ) = 2 * 32 * 48 ( 32 + 48 ) = 38.4 answer : c"
Answer: C