Winnie purchased a bottle of pomegranate syrup to make drinks. She used ¹₃ of the syrup in April. She then used the remaining syrup in May and June in the ratio 2 : 5. Given that the amount of the pomegranate syrup used in April was 0.39 ℓ more than that in May, how many millilitres of pomegranate syrup did the bottle contain at first?

April	May	June	Total
1x7	2x7		3x7
	2x2	5x2
7 u	4 u	10 u	21 u

Total volume of May and June is combined repeated identity.  Make the total volume of May and June the same.  LCM of 2 and 7 is 14.

Volume of more pomegranate syrup in the bottle used in April than May
= 7 u - 4 u
= 3 u

3 u = 0.39 

1 u = 0.39 ÷ 3 = 0.13

Amount of pomegranate syrup in the bottle at first
= 21 u
= 21 x 0.13
= 2.73 ℓ

1 ℓ = 1000 mℓ

Amount of pomegranate syrup in the bottle at first
= 2.73 x 1000
= 2730 mℓ

Answer(s): 2730 mℓ