Erika purchased a bottle of starfruit syrup to make drinks. She used ³₈ of the syrup in March. She then used the remaining syrup in April and May in the ratio 2 : 5. Given that the amount of the starfruit syrup used in March was 0.22 ℓ more than that in April, how many millilitres of starfruit syrup did the bottle contain at first?

March	April	May	Total
3x7	5x7		8x7
	2x5	5x5
21 u	10 u	25 u	56 u

Total volume of April and May is combined repeated identity.  Make the total volume of April and May the same.  LCM of 5 and 7 is 35.

Volume of more starfruit syrup in the bottle used in March than April
= 21 u - 10 u
= 11 u

11 u = 0.22 

1 u = 0.22 ÷ 11 = 0.02

Amount of starfruit syrup in the bottle at first
= 56 u
= 56 x 0.02
= 1.12 ℓ

1 ℓ = 1000 mℓ

Amount of starfruit syrup in the bottle at first
= 1.12 x 1000
= 1120 mℓ

Answer(s): 1120 mℓ