Olivia purchased a bottle of vinegar. She used ⁷₁₀ of the vinegar in April. She then used the remaining vinegar in May and June in the ratio 1 : 6. Given that the amount of the vinegar used in June was 0.93 ℓ less than that in April, how many millilitres of vinegar did the bottle contain at first?

April	May	June	Total
7x7	3x7		10x7
	1x3	6x3
49 u	3 u	18 u	70 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 vinegar syrup in the bottle used in June than April
= 49 u - 18 u
= 31 u

31 u = 0.93 

1 u = 0.93 ÷ 31 = 0.03

Amount of vinegar in the bottle at first
= 70 u
= 70 x 0.03
= 2.1 ℓ

1 ℓ = 1000 mℓ

Amount of vinegar in the bottle at first
= 2.1 x 1000
= 2100 mℓ

Answer(s): 2100 mℓ