Marion purchased a bottle of mangosteen syrup to make drinks. She used ⁵₈ of the syrup in January. She then used the remaining syrup in February and March in the ratio 1 : 4. Given that the amount of the mangosteen syrup used in January was 1.32 ℓ more than that in February, how many millilitres of mangosteen syrup did the bottle contain at first?

January	February	March	Total
5x5	3x5		8x5
	1x3	4x3
25 u	3 u	12 u	40 u

Total volume of February and March is combined repeated identity.  Make the total volume of February and March the same.  LCM of 3 and 5 is 15.

Volume of more mangosteen syrup in the bottle used in January than February
= 25 u - 3 u
= 22 u

22 u = 1.32 

1 u = 1.32 ÷ 22 = 0.06

Amount of mangosteen syrup in the bottle at first
= 40 u
= 40 x 0.06
= 2.4 ℓ

1 ℓ = 1000 mℓ

Amount of mangosteen syrup in the bottle at first
= 2.4 x 1000
= 2400 mℓ

Answer(s): 2400 mℓ