PSLE
There was a total of 19138 cm³ of water in rectangular tanks H and J at first. The height of the water level in tank J was 4 cm above that of tank H.

1. Find the height of the water level in tank H.
2. Tina poured 5568 cm³ of water out of tank J. Tank J was then half filled with water. What was the height of tank J?

(a)
Volume of water in Tank J with a height of 4 cm
= 29 x 24 x 4
= 2784 cm³

Volume of water in both tanks excluding the water that is 4 cm above that of Tank H
= 19138 - 2784
= 16354 cm³

Base area of Tank H
= 19 x 14
= 266 cm²

Base area of Tank J
= 29 x 24
= 696 cm²

Combined base areas of both tanks
= 266 + 696
= 962 cm²

Height of water in Tank H 
= 16354 ÷ 962
= 17 cm

(b)
Decrease in the height of Tank J after some water was poured out 
= 5568 ÷ 696
= 8 cm

Original height of water before some was poured out
= 17 + 4
= 21 cm

Height of water after some was poured out
= 21 - 8
= 13 cm

Height of Tank H
= 2 x 13
= 26 cm

Answer(s): (a) 17 cm; (b) 26 cm