Jeremy and Fabian each had the same volume of water. The water was used to pour into identical bottles. Jeremy filled up 20 bottles and had 8.5 ℓ of water left. Fabian filled up 12 bottles and had 10.9 ℓ of water left.

1. What was the capacity of each bottle? Give your answer in millilitres.
2. What was the total volume of water Jeremy and Fabian had at first? Give your answer in litres.

(a)
Difference between the number of bottles
= 20 - 12
= 8

Difference between the volume of water left
= 10.9 - 8.5
= 2.4 ℓ

Volume of 8 bottles = 2.4 ℓ

Volume of 1 bottle
= 2.4 ÷ 8
= 0.3 ℓ

1 ℓ = 1000 mℓ
0.3 ℓ = 0.3 x 1000 = 300 mℓ

(b)
Volume of 12 bottles 
= 12 x 0.3
= 3.6 ℓ

Volume of water that Fabian had at first
= 3.6 + 10.9
= 14.5 ℓ

Total volume of water that Jeremy and Fabian had at first
= 2 x 14.5
= 29 ℓ

Answer(s): (a) 300 mℓ (b) 29 ℓ