PSLE
There was a total of 19087 cm³ of water in rectangular tanks T and U at first. The height of the water level in tank U was 5 cm above that of tank T.

1. Find the height of the water level in tank T.
2. Cindy poured 4992 cm³ of water out of tank U. Tank U was then half filled with water. What was the height of tank U?

(a)
Volume of water in Tank U with a height of 5 cm
= 32 x 26 x 5
= 4160 cm³

Volume of water in both tanks excluding the water that is 5 cm above that of Tank T
= 19087 - 4160
= 14927 cm³

Base area of Tank T
= 25 x 21
= 525 cm²

Base area of Tank U
= 32 x 26
= 832 cm²

Combined base areas of both tanks
= 525 + 832
= 1357 cm²

Height of water in Tank T 
= 14927 ÷ 1357
= 11 cm

(b)
Decrease in the height of Tank U after some water was poured out 
= 4992 ÷ 832
= 6 cm

Original height of water before some was poured out
= 11 + 5
= 16 cm

Height of water after some was poured out
= 16 - 6
= 10 cm

Height of Tank T
= 2 x 10
= 20 cm

Answer(s): (a) 11 cm; (b) 20 cm