PSLE
At first, Containers F, G and H contained water as shown in Figure 1. Some water from F and G was poured into Container H without spilling. The amount of water left in Container F and G is shown in Figure 2. What would be the amount of water in Container H?
1 ℓ = 1000 mℓ

Container F 
10 intervals = 500
1 interval = 500 ÷ 10 = 50

Decrease in the volume of water in Container F
= 2 intervals of Container F
= 2 x 50
= 100 mℓ

Container G
10 intervals = 200
1 interval = 200 ÷ 10 = 20

Decrease in the volume of water in Container G
= 2 intervals of Container G
= 2 x 20 
= 40 mℓ

Container H
10 intervals = 1000
1 interval = 1000 ÷ 10 = 100

Volume of water in Container H at first
= 2 intervals of Container H
= 2 x 100
= 200 mℓ

Total decrease in volume of water in Containers F and G
= 100 + 40
= 140 mℓ

Volume of water in Container H in the end
= 200 + 140
= 340 mℓ

Answer(s): 340 mℓ