Hilda purchased a bottle of persimmon syrup to make drinks. She used ³₅ of the syrup in January. She then used the remaining syrup in February and March in the ratio 1 : 2. Given that the amount of the persimmon syrup used in January was 0.21 ℓ more than that in February, how many millilitres of persimmon syrup did the bottle contain at first?

January	February	March	Total
3x3	2x3		5x3
	1x2	2x2
9 u	2 u	4 u	15 u

Total volume of February and March is combined repeated identity.  Make the total volume of February and March the same.  LCM of 2 and 3 is 6.

Volume of more persimmon syrup in the bottle used in January than February
= 9 u - 2 u
= 7 u

7 u = 0.21 

1 u = 0.21 ÷ 7 = 0.03

Amount of persimmon syrup in the bottle at first
= 15 u
= 15 x 0.03
= 0.45 ℓ

1 ℓ = 1000 mℓ

Amount of persimmon syrup in the bottle at first
= 0.45 x 1000
= 450 mℓ

Answer(s): 450 mℓ