PSLE There was a total of 9854 cm
3 of water in rectangular tanks E and F at first. The height of the water level in tank F was 2 cm above that of tank E.
- Find the height of the water level in tank E.
- Jade poured 2800 cm3 of water out of tank F. Tank F was then half filled with water. What was the height of tank F?
(a)
Volume of water in Tank F with a height of 2 cm
= 28 x 20 x 2
= 1120 cm
3 Volume of water in both tanks excluding the water that is 2 cm above that of Tank E
= 9854 - 1120
= 8734 cm
3 Base area of Tank E
= 18 x 13
= 234 cm
2 Base area of Tank F
= 28 x 20
= 560 cm
2 Combined base areas of both tanks
= 234 + 560
= 794 cm
2 Height of water in Tank E
= 8734 ÷ 794
= 11 cm
(b)
Decrease in the height of Tank F after some water was poured out
= 2800 ÷ 560
= 5 cm
Original height of water before some was poured out
= 11 + 2
= 13 cm
Height of water after some was poured out
= 13 - 5
= 8 cm
Height of Tank E
= 2 x 8
= 16 cm
Answer(s): (a) 11 cm; (b) 16 cm