PSLE There was a total of 26452 cm
3 of water in rectangular tanks N and P at first. The height of the water level in tank P was 5 cm above that of tank N.
- Find the height of the water level in tank N.
- Shiyun poured 6006 cm3 of water out of tank P. Tank P was then half filled with water. What was the height of tank P?
(a)
Volume of water in Tank P with a height of 5 cm
= 33 x 26 x 5
= 4290 cm
3 Volume of water in both tanks excluding the water that is 5 cm above that of Tank N
= 26452 - 4290
= 22162 cm
3 Base area of Tank N
= 29 x 25
= 725 cm
2 Base area of Tank P
= 33 x 26
= 858 cm
2 Combined base areas of both tanks
= 725 + 858
= 1583 cm
2 Height of water in Tank N
= 22162 ÷ 1583
= 14 cm
(b)
Decrease in the height of Tank P after some water was poured out
= 6006 ÷ 858
= 7 cm
Original height of water before some was poured out
= 14 + 5
= 19 cm
Height of water after some was poured out
= 19 - 7
= 12 cm
Height of Tank N
= 2 x 12
= 24 cm
Answer(s): (a) 14 cm; (b) 24 cm