Answer:
a. 10 km
b. 25 km
c. 35 km
Explanation:
You are given the rate running = 5 km per 0.5 hr and the rate for biking = 20 km per 0.8 hr. Set up a proportion to get from 0.5 hr to 1 hr multiply by 2, so multiply 5 km by 2 = 10 km. Do the same for biking 0.8 hr to 1 hr is multiplied by 1.25, so multiply 20 by 1.25 = 25 km. Add those two values together for c to get 35 km. See attached image