PSLE There was a total of 31450 cm
3 of water in rectangular tanks E and F at first. The height of the water level in tank F was 3 cm above that of tank E.
- Find the height of the water level in tank E.
- Sarah poured 3536 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 3 cm
= 34 x 26 x 3
= 2652 cm
3 Volume of water in both tanks excluding the water that is 3 cm above that of Tank E
= 31450 - 2652
= 28798 cm
3 Base area of Tank E
= 30 x 27
= 810 cm
2 Base area of Tank F
= 34 x 26
= 884 cm
2 Combined base areas of both tanks
= 810 + 884
= 1694 cm
2 Height of water in Tank E
= 28798 ÷ 1694
= 17 cm
(b)
Decrease in the height of Tank F after some water was poured out
= 3536 ÷ 884
= 4 cm
Original height of water before some was poured out
= 17 + 3
= 20 cm
Height of water after some was poured out
= 20 - 4
= 16 cm
Height of Tank E
= 2 x 16
= 32 cm
Answer(s): (a) 17 cm; (b) 32 cm