Question

if 5 litres of petrol cost rupees 90 how much will 8 litres of petrol cost

Answer 1

5 L equals 90 rupees
1 L 5/90
8 L = 5/90×8

Answer 2

hi friend
here's your answer looking for

The cost of 1 litre petrol =

$\frac{90}{5} \\ \\ = 18rs$
and now,

cost of 8 litre petrol =

$8 \times 18 \\ \\ = 144rs$

hope you are satisfied with my answer