Question

Mark cycles from home to school at a speed of 16 kilometers per hour. He cycles back on the

same route at a speed of 15 kilometers per hour. The total time taken for the journey is 7 3/4
hours. Given that the distance for his home to school is d kilometers, and that distance -
speed - time, write and solve an equation to find the total distance traveled by him.

Answer 1

Write a time equation, time = dist/speed

:

go time + return time = total time

d%2F16 + d%2F15 = 7.75 hrs

multiply equation by the least common multiple 240, cncel the denominators:

15d + 16d = 240(7.75)

31d = 1860

d = 1860/31

d = 60 km one way

total dist = 120 km

:

Check this, find the actual time each way

60/16 = 3.75 hrs

60/15 = 4 hrs

-----------------

total time 7.75 hrs

Explanation: