Daniel and Tommy each had the same volume of water. The water was used to pour into identical bottles. Daniel filled up 12 bottles and had 10.9 ℓ of water left. Tommy filled up 6 bottles and had 12.7 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 Daniel and Tommy had at first? Give your answer in litres.

(a)
Difference between the number of bottles
= 12 - 6
= 6

Difference between the volume of water left
= 12.7 - 10.9
= 1.8 ℓ

Volume of 6 bottles = 1.8 ℓ

Volume of 1 bottle
= 1.8 ÷ 6
= 0.3 ℓ

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

(b)
Volume of 6 bottles 
= 6 x 0.3
= 1.8 ℓ

Volume of water that Tommy had at first
= 1.8 + 12.7
= 14.5 ℓ

Total volume of water that Daniel and Tommy had at first
= 2 x 14.5
= 29 ℓ

Answer(s): (a) 300 mℓ (b) 29 ℓ