Question

A car consumes one litre of petrol every two fifths of the distance covered. How many litres of fuel are needed by a car to cover a distance of 55km?

Answer 1

d = distance

d = 55 km

d / 5 = 11 km

Two fifths of the distance =

2 / 5 d = 2 • d / 5 = 2 • 11 km = 22 km

A car consumes one litre of petrol every 22 km.

Ratio:

1 / 22 = x / 55

where

x = fuel needed by a car to cover 55km

Cross multiply.

1 •. 55 = x • 22

55 = 22 x

22 x = 55

x = 55 / 22 = 11 • 5 / 11 • 2 =

5 / 2 = 2.5

Car to cover a distance of 55 km needed 2.5 litres of fuel.

OR

A car consumes one litre of petrol every 22 km.

11 km = 0.5 • 22 km

This means a car consumes 0.5 litres of petrol every 11 km.

55 km = 5 • 11 km

5 • 0.5 liter = 2.5 liters

Answer 2

2/5×55=22km
22km=1 litre
55km=??
=55/22
=2.5 litres