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

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

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

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

Decrease in the volume of water in Container C
= 3 intervals of Container C
= 3 x 20 
= 60 mℓ

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

Volume of water in Container D at first
= 6 intervals of Container D
= 6 x 100
= 600 mℓ

Total decrease in volume of water in Containers B and C
= 100 + 60
= 160 mℓ

Volume of water in Container D in the end
= 600 + 160
= 760 mℓ

Answer(s): 760 mℓ