PSLE There was a total of 39732 cm
3 of water in rectangular tanks U and V at first. The height of the water level in tank V was 2 cm above that of tank U.
- Find the height of the water level in tank U.
- Penelope poured 9672 cm3 of water out of tank V. Tank V was then half filled with water. What was the height of tank V?
(a)
Volume of water in Tank V with a height of 2 cm
= 39 x 31 x 2
= 2418 cm
3 Volume of water in both tanks excluding the water that is 2 cm above that of Tank U
= 39732 - 2418
= 37314 cm
3 Base area of Tank U
= 32 x 27
= 864 cm
2 Base area of Tank V
= 39 x 31
= 1209 cm
2 Combined base areas of both tanks
= 864 + 1209
= 2073 cm
2 Height of water in Tank U
= 37314 ÷ 2073
= 18 cm
(b)
Decrease in the height of Tank V after some water was poured out
= 9672 ÷ 1209
= 8 cm
Original height of water before some was poured out
= 18 + 2
= 20 cm
Height of water after some was poured out
= 20 - 8
= 12 cm
Height of Tank U
= 2 x 12
= 24 cm
Answer(s): (a) 18 cm; (b) 24 cm