Question

A car covers 20 km in the first hour and 30 km in the last 4 hours. Find:
i) Speed of car in the first hour
ii) Speed of the car in the last four hours
iii) Average speed of the car [3 MARKS]

Answer 1

Each part: 1 Mark

i) Speed of the car in the first hour $=\frac{Distance}{time}$
$=\frac{20}{1}\frac{km}{hr}$
= 20 km/hr
ii) Speed of the car in the last 4 hours $=\frac{Distance}{time}$
$=\frac{30}{4}\frac{km}{hr}$
= 7.5 km/hr

iii) Total distance covered = 20 + 30 = 50 km

Total time taken = 1 + 4 = 5 hrs

Average speed $=\frac{TotalDistance}{Totaltime}=\frac{50}{5}$
= 10 km/hr