PSLE There was a total of 35584 cm
3 of water in rectangular tanks Q and R at first. The height of the water level in tank R was 5 cm above that of tank Q.
- Find the height of the water level in tank Q.
- Kimberly poured 8960 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 5 cm
= 40 x 32 x 5
= 6400 cm
3 Volume of water in both tanks excluding the water that is 5 cm above that of Tank Q
= 35584 - 6400
= 29184 cm
3 Base area of Tank Q
= 36 x 32
= 1152 cm
2 Base area of Tank R
= 40 x 32
= 1280 cm
2 Combined base areas of both tanks
= 1152 + 1280
= 2432 cm
2 Height of water in Tank Q
= 29184 ÷ 2432
= 12 cm
(b)
Decrease in the height of Tank R after some water was poured out
= 8960 ÷ 1280
= 7 cm
Original height of water before some was poured out
= 12 + 5
= 17 cm
Height of water after some was poured out
= 17 - 7
= 10 cm
Height of Tank Q
= 2 x 10
= 20 cm
Answer(s): (a) 12 cm; (b) 20 cm