PSLE There was a total of 28220 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.
- Sabrina poured 6800 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
= 40 x 34 x 3
= 4080 cm
3 Volume of water in both tanks excluding the water that is 3 cm above that of Tank F
= 28220 - 4080
= 24140 cm
3 Base area of Tank F
= 34 x 31
= 1054 cm
2 Base area of Tank G
= 40 x 34
= 1360 cm
2 Combined base areas of both tanks
= 1054 + 1360
= 2414 cm
2 Height of water in Tank F
= 24140 ÷ 2414
= 10 cm
(b)
Decrease in the height of Tank G after some water was poured out
= 6800 ÷ 1360
= 5 cm
Original height of water before some was poured out
= 10 + 3
= 13 cm
Height of water after some was poured out
= 13 - 5
= 8 cm
Height of Tank F
= 2 x 8
= 16 cm
Answer(s): (a) 10 cm; (b) 16 cm