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