Question

Irina rode her bike to work at an average speed of 16 miles per hour. It started to rain, so she got a ride home along the same route in her coworker’s car at an average speed of 27 miles per hour. If Irina’s ride home in the car took 24 minutes (0.4 of an hour), how many hours was her bike ride to work, to the nearest tenth of an hour?

Answer 1

0.7 hours

Explanation:

Given that Irina was able to make the same distance from work to home in 0.4 of an hour at 27 miles per hour, we can use this rate and time to find the distance she travels to and from work using the general formula:

d = rt, where d=distance, r = rate and t = time

d = 27(0.4) = 10.8 miles

Since the distance from Irina's home to work is 10.8 miles, we can again use the formula 'd = rt' to find the time it takes her to bike to work at a rate of 16 miles per hour and solving for time, 't':

10.8 = (16)t

t = 0.7 hours