Question

they travelled 551 km from Bagani to Zimbabwe N.R at an average speed of 75km/h and their car has an average petrol consumption of 12 litres per 100 km . calculate the following .
1. the time that it will take them to complete the journey , convert to hours & minutes .
2. the amount that they will spend on petrol if the petrol costs is R7.25 per litre ?

Answer 1

a]  the time that it will take them to complete the journey , convert to hours & minutes .
Time=(distance)/(speed)
distance=551
speed=75 km/h
thus
time=551/75=7 26/75 hours
=7 hours (26/75×60) min
=7 hours 21 min

2] the amount that they will spend on petrol if the petrol costs is R7.25 per litre ?
Total amount spent on petrol will be as follows:
Cost of petrol R7.25 per Km
Consumption=12 liters per 100 km
thus amount of liters used:
12/100×551
=66.12 liters
thus total cost of petrol used:
66.12×7.25
=R479.37