PSLE There was a total of 20272 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.
- Gwen poured 2464 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 22 x 2
= 1232 cm
3 Volume of water in both tanks excluding the water that is 2 cm above that of Tank E
= 20272 - 1232
= 19040 cm
3 Base area of Tank E
= 24 x 21
= 504 cm
2 Base area of Tank F
= 28 x 22
= 616 cm
2 Combined base areas of both tanks
= 504 + 616
= 1120 cm
2 Height of water in Tank E
= 19040 ÷ 1120
= 17 cm
(b)
Decrease in the height of Tank F after some water was poured out
= 2464 ÷ 616
= 4 cm
Original height of water before some was poured out
= 17 + 2
= 19 cm
Height of water after some was poured out
= 19 - 4
= 15 cm
Height of Tank E
= 2 x 15
= 30 cm
Answer(s): (a) 17 cm; (b) 30 cm