Question

if half a litre of milk cost 22 rupees how much will 7 litres cost ?

Answer 1

when we cross multiply we get rs 308
half a litre= 0.5L

0.5L = Rs 22
7L    = Rs?

on cross multiplying:
7×22/0.5
multiply denominator and numerator with 10
7×220/5
7×44
Rs 308

Answer 2

hi friend

here is your answer looking for

cost of half litre = 2×22 = 44

cost of 7 litre =

$44 \times 7 \\ \\ = 308$

7 cost is = Rs 308

hope you are satisfied with my answer .