PSLE
There was a total of 17404 cm³ of water in rectangular tanks G and H at first. The height of the water level in tank H was 2 cm above that of tank G.

1. Find the height of the water level in tank G.
2. Xandra poured 3458 cm³ of water out of tank H. Tank H was then half filled with water. What was the height of tank H?

(a)
Volume of water in Tank H with a height of 2 cm
= 26 x 19 x 2
= 988 cm³

Volume of water in both tanks excluding the water that is 2 cm above that of Tank G
= 17404 - 988
= 16416 cm³

Base area of Tank G
= 22 x 19
= 418 cm²

Base area of Tank H
= 26 x 19
= 494 cm²

Combined base areas of both tanks
= 418 + 494
= 912 cm²

Height of water in Tank G 
= 16416 ÷ 912
= 18 cm

(b)
Decrease in the height of Tank H after some water was poured out 
= 3458 ÷ 494
= 7 cm

Original height of water before some was poured out
= 18 + 2
= 20 cm

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

Height of Tank G
= 2 x 13
= 26 cm

Answer(s): (a) 18 cm; (b) 26 cm