Eva purchased a bottle of passion fruit syrup to make drinks. She used ¹₃ of the syrup in February. She then used the remaining syrup in March and April in the ratio 2 : 9. Given that the amount of the passion fruit syrup used in February was 0.35 ℓ more than that in March, how many millilitres of passion fruit syrup did the bottle contain at first?

February	March	April	Total
1x11	2x11		3x11
	2x2	9x2
11 u	4 u	18 u	33 u

Total volume of March and April is combined repeated identity.  Make the total volume of March and April the same.  LCM of 2 and 11 is 22.

Volume of more passion fruit syrup in the bottle used in February than March
= 11 u - 4 u
= 7 u

7 u = 0.35 

1 u = 0.35 ÷ 7 = 0.05

Amount of passion fruit syrup in the bottle at first
= 33 u
= 33 x 0.05
= 1.65 ℓ

1 ℓ = 1000 mℓ

Amount of passion fruit syrup in the bottle at first
= 1.65 x 1000
= 1650 mℓ

Answer(s): 1650 mℓ