PSLE There was a total of 30708 cm
3 of water in rectangular tanks F and G at first. The height of the water level in tank G was 3 cm above that of tank F.
- Find the height of the water level in tank F.
- Abi poured 4680 cm3 of water out of tank G. Tank G was then half filled with water. What was the height of tank G?
(a)
Volume of water in Tank G with a height of 3 cm
= 36 x 26 x 3
= 2808 cm
3 Volume of water in both tanks excluding the water that is 3 cm above that of Tank F
= 30708 - 2808
= 27900 cm
3 Base area of Tank F
= 33 x 28
= 924 cm
2 Base area of Tank G
= 36 x 26
= 936 cm
2 Combined base areas of both tanks
= 924 + 936
= 1860 cm
2 Height of water in Tank F
= 27900 ÷ 1860
= 15 cm
(b)
Decrease in the height of Tank G after some water was poured out
= 4680 ÷ 936
= 5 cm
Original height of water before some was poured out
= 15 + 3
= 18 cm
Height of water after some was poured out
= 18 - 5
= 13 cm
Height of Tank F
= 2 x 13
= 26 cm
Answer(s): (a) 15 cm; (b) 26 cm