PSLE There was a total of 18012 cm
3 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.
- Find the height of the water level in tank T.
- Rachel poured 4104 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
= 27 x 19 x 5
= 2565 cm
3 Volume of water in both tanks excluding the water that is 5 cm above that of Tank T
= 18012 - 2565
= 15447 cm
3 Base area of Tank T
= 20 x 15
= 300 cm
2 Base area of Tank U
= 27 x 19
= 513 cm
2 Combined base areas of both tanks
= 300 + 513
= 813 cm
2 Height of water in Tank T
= 15447 ÷ 813
= 19 cm
(b)
Decrease in the height of Tank U after some water was poured out
= 4104 ÷ 513
= 8 cm
Original height of water before some was poured out
= 19 + 5
= 24 cm
Height of water after some was poured out
= 24 - 8
= 16 cm
Height of Tank T
= 2 x 16
= 32 cm
Answer(s): (a) 19 cm; (b) 32 cm