Question

3. A pupil left home for school at a speed of

5 km/h and returned at a speed of 4 km/h
The whole journey took 5 h 24 min.
How far is the school from home, in
kilometres
A 9
B. 12
C. 24
D. 27​

Answer 1

12 km

Explanation:

• 5h 24min = 5.4 hr
• time = distance / speed

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

time out + time back = total time

d/5 + d/4 = 5.4

multiply both sides by 20 to clear the fractions

4d + 5d = 108

9d = 108

Divide both sides by 9

d = 12 km