PSLE There was a total of 19240 cm
3 of water in rectangular tanks Q and R at first. The height of the water level in tank R was 2 cm above that of tank Q.
- Find the height of the water level in tank Q.
- Esther poured 3536 cm3 of water out of tank R. Tank R was then half filled with water. What was the height of tank R?
(a)
Volume of water in Tank R with a height of 2 cm
= 34 x 26 x 2
= 1768 cm
3 Volume of water in both tanks excluding the water that is 2 cm above that of Tank Q
= 19240 - 1768
= 17472 cm
3 Base area of Tank Q
= 26 x 22
= 572 cm
2 Base area of Tank R
= 34 x 26
= 884 cm
2 Combined base areas of both tanks
= 572 + 884
= 1456 cm
2 Height of water in Tank Q
= 17472 ÷ 1456
= 12 cm
(b)
Decrease in the height of Tank R after some water was poured out
= 3536 ÷ 884
= 4 cm
Original height of water before some was poured out
= 12 + 2
= 14 cm
Height of water after some was poured out
= 14 - 4
= 10 cm
Height of Tank Q
= 2 x 10
= 20 cm
Answer(s): (a) 12 cm; (b) 20 cm