PSLE
There was a total of 12352 cm³ of water in rectangular tanks A and B at first. The height of the water level in tank B was 4 cm above that of tank A.

1. Find the height of the water level in tank A.
2. Sarah poured 2912 cm³ of water out of tank B. Tank B was then half filled with water. What was the height of tank B?

(a)
Volume of water in Tank B with a height of 4 cm
= 26 x 16 x 4
= 1664 cm³

Volume of water in both tanks excluding the water that is 4 cm above that of Tank A
= 12352 - 1664
= 10688 cm³

Base area of Tank A
= 18 x 14
= 252 cm²

Base area of Tank B
= 26 x 16
= 416 cm²

Combined base areas of both tanks
= 252 + 416
= 668 cm²

Height of water in Tank A 
= 10688 ÷ 668
= 16 cm

(b)
Decrease in the height of Tank B after some water was poured out 
= 2912 ÷ 416
= 7 cm

Original height of water before some was poured out
= 16 + 4
= 20 cm

Height of water after some was poured out
= 20 - 7
= 13 cm

Height of Tank A
= 2 x 13
= 26 cm

Answer(s): (a) 16 cm; (b) 26 cm