A cyclist rides a bicycle 7 km at an average speed of 10 km/hr and again travels 10 km at an average speed of 7 km/hr. What is the average speed for the entire trip?  Choose the correct option: A) 7.59 B) 7.79 C) 7.99 D) 8.19 E) 8.39
distance = 17 km   time = 7/10 + 10/7 = (49 + 100) / 70 = 149 / 70 hours   average speed = (17 * 70) / 149 = 7.99 km/h   The answer is 7.99.
<result>C</result>
A cyclist rides a bicycle 7 km at an average speed of 10 km/hr and again travels 10 km at an average speed of 7 km/hr. What is the average speed for the entire trip?