Answer:
a) 15.75 minutes
b) 3.54 km
Explanation:
Given speeds to school and back of 13.5 km/h and 10.5 km/h, respectively, and a total travel time of 36 minutes, you want to know the time to ride to school, and the distance.
Ratio
The ratio of times is the inverse of the ratio of speeds over the same distance. The ratio of times is ...
time to school : time to home = 10.5 : 13.5 = 7 : 9
a) Time
Then the fraction of total time it takes to get to school is ...
(7/(7+9))·(36 min) = 15.75 min = 0.2625 hour . . . . . . . 1 min = 1/60 hour
b) Distance
The distance can be found from the relation ...
distance = speed · time
distance = (13.5 km/h)(0.2625 h) = 3.54375 km ≈ 3.54 km
It takes Torrin 15.75 minutes to ride the 3.54 km to school.