PSLE
There was a total of 26292 cm³ of water in rectangular tanks D and E at first. The height of the water level in tank E was 2 cm above that of tank D.

1. Find the height of the water level in tank D.
2. Hazel poured 4440 cm³ of water out of tank E. Tank E was then half filled with water. What was the height of tank E?

(a)
Volume of water in Tank E with a height of 2 cm
= 37 x 30 x 2
= 2220 cm³

Volume of water in both tanks excluding the water that is 2 cm above that of Tank D
= 26292 - 2220
= 24072 cm³

Base area of Tank D
= 32 x 28
= 896 cm²

Base area of Tank E
= 37 x 30
= 1110 cm²

Combined base areas of both tanks
= 896 + 1110
= 2006 cm²

Height of water in Tank D 
= 24072 ÷ 2006
= 12 cm

(b)
Decrease in the height of Tank E after some water was poured out 
= 4440 ÷ 1110
= 4 cm

Original height of water before some was poured out
= 12 + 2
= 14 cm

Height of water after some was poured out
= 14 - 4
= 10 cm

Height of Tank D
= 2 x 10
= 20 cm

Answer(s): (a) 12 cm; (b) 20 cm