Japheth and Jeremy each had the same volume of water. The water was used to pour into identical bottles. Japheth filled up 10 bottles and had 6.5 ℓ of water left. Jeremy filled up 6 bottles and had 9.3 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 Japheth and Jeremy had at first? Give your answer in litres.

(a)
Difference between the number of bottles
= 10 - 6
= 4

Difference between the volume of water left
= 9.3 - 6.5
= 2.8 ℓ

Volume of 4 bottles = 2.8 ℓ

Volume of 1 bottle
= 2.8 ÷ 4
= 0.7 ℓ

1 ℓ = 1000 mℓ
0.7 ℓ = 0.7 x 1000 = 700 mℓ

(b)
Volume of 6 bottles 
= 6 x 0.7
= 4.2 ℓ

Volume of water that Jeremy had at first
= 4.2 + 9.3
= 13.5 ℓ

Total volume of water that Japheth and Jeremy had at first
= 2 x 13.5
= 27 ℓ

Answer(s): (a) 700 mℓ (b) 27 ℓ