Yoko purchased a bottle of maple syrup. She used ⁵₉ of the maple syrup in January. She then used the remaining maple syrup in February and March in the ratio 1 : 2. Given that the amount of the maple syrup used in March was 0.42 ℓ less than that in January, how many millilitres of maple syrup did the bottle contain at first?

January	February	March	Total
5x3	4x3		9x3
	1x4	2x4
15 u	4 u	8 u	27 u

Total volume of February and March is combined repeated identity. Make the total volume of February and March the same. LCM of 4 and 3 is 12.

Volume of less maple syrup syrup in the bottle used in March than January
= 15 u - 8 u
= 7 u

7 u = 0.42 

1 u = 0.42 ÷ 7 = 0.06

Amount of maple syrup in the bottle at first
= 27 u
= 27 x 0.06
= 1.62 ℓ

1 ℓ = 1000 mℓ

Amount of maple syrup in the bottle at first
= 1.62 x 1000
= 1620 mℓ

Answer(s): 1620 mℓ