A cyclist rides a bicycle 9 km at an average speed of 11 km/hr and again travels 11 km at an average speed of 9 km/hr. What is the average speed for the entire trip? Choices: A) 9.3 B) 9.6 C) 9.8 D) 10.1 E) 10.3

Rationale: "distance = 20 km time = 9 / 11 + 11 / 9 = ( 81 + 121 ) / 99 = 202 / 99 hours average speed = ( 20 * 99 ) / 202 = 9.8 km / h the answer is c ."
Answer: C