Xandra purchased a bottle of oil. She used ²₅ of the oil in April. She then used the remaining oil in May and June in the ratio 3 : 4. Given that the amount of the oil used in June was 0.06 ℓ less than that in April, how many millilitres of oil did the bottle contain at first?

April	May	June	Total
2x7	3x7		5x7
	3x3	4x3
14 u	9 u	12 u	35 u

Total volume of May and June is combined repeated identity. Make the total volume of May and June the same. LCM of 3 and 7 is 21.

Volume of less oil syrup in the bottle used in June than April
= 14 u - 12 u
= 2 u

2 u = 0.06 

1 u = 0.06 ÷ 2 = 0.03

Amount of oil in the bottle at first
= 35 u
= 35 x 0.03
= 1.05 ℓ

1 ℓ = 1000 mℓ

Amount of oil in the bottle at first
= 1.05 x 1000
= 1050 mℓ

Answer(s): 1050 mℓ