PSLE There was a total of 18806 cm
3 of water in rectangular tanks F and G at first. The height of the water level in tank G was 7 cm above that of tank F.
- Find the height of the water level in tank F.
- Linda poured 3600 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 7 cm
= 25 x 18 x 7
= 3150 cm
3 Volume of water in both tanks excluding the water that is 7 cm above that of Tank F
= 18806 - 3150
= 15656 cm
3 Base area of Tank F
= 22 x 17
= 374 cm
2 Base area of Tank G
= 25 x 18
= 450 cm
2 Combined base areas of both tanks
= 374 + 450
= 824 cm
2 Height of water in Tank F
= 15656 ÷ 824
= 19 cm
(b)
Decrease in the height of Tank G after some water was poured out
= 3600 ÷ 450
= 8 cm
Original height of water before some was poured out
= 19 + 7
= 26 cm
Height of water after some was poured out
= 26 - 8
= 18 cm
Height of Tank F
= 2 x 18
= 36 cm
Answer(s): (a) 19 cm; (b) 36 cm