PSLE There was a total of 26022 cm
3 of water in rectangular tanks M and N at first. The height of the water level in tank N was 4 cm above that of tank M.
- Find the height of the water level in tank M.
- Xandra poured 6006 cm3 of water out of tank N. Tank N was then half filled with water. What was the height of tank N?
(a)
Volume of water in Tank N with a height of 4 cm
= 33 x 26 x 4
= 3432 cm
3 Volume of water in both tanks excluding the water that is 4 cm above that of Tank M
= 26022 - 3432
= 22590 cm
3 Base area of Tank M
= 27 x 24
= 648 cm
2 Base area of Tank N
= 33 x 26
= 858 cm
2 Combined base areas of both tanks
= 648 + 858
= 1506 cm
2 Height of water in Tank M
= 22590 ÷ 1506
= 15 cm
(b)
Decrease in the height of Tank N after some water was poured out
= 6006 ÷ 858
= 7 cm
Original height of water before some was poured out
= 15 + 4
= 19 cm
Height of water after some was poured out
= 19 - 7
= 12 cm
Height of Tank M
= 2 x 12
= 24 cm
Answer(s): (a) 15 cm; (b) 24 cm