Question

Mark (✓) against the correct answer:
A car is travelling at an average speed of 60 km per hour. How much distance will it cover in 1 hour 12 minutes?
(a) 50 km
(b) 72 km
(c) 63 km
(d) 67.2 km

Answer 1

(b) 72 km
Let x km be the distance covered in 1 h 12 min.
Now, 1 h 12 min = (60+12) min = 72 min

Distance(in km)	60	$x$
Time(in min)	60	72

More distance will be covered in more time.
So, it is a cas of direct proportion.

$$\begin{gathered} \mathrm{Now},\frac{60}{60}=\frac{x}{72} \\ \Rightarrow x=72\mathrm{km} \end{gathered}$$

∴ The car will cover a distance of 72 $\mathrm{km}$ in 1 h 12 min.​