PSLE There was a total of 27840 cm
3 of water in rectangular tanks W and X at first. The height of the water level in tank X was 2 cm above that of tank W.
- Find the height of the water level in tank W.
- Diana poured 3393 cm3 of water out of tank X. Tank X was then half filled with water. What was the height of tank X?
(a)
Volume of water in Tank X with a height of 2 cm
= 39 x 29 x 2
= 2262 cm
3 Volume of water in both tanks excluding the water that is 2 cm above that of Tank W
= 27840 - 2262
= 25578 cm
3 Base area of Tank W
= 29 x 24
= 696 cm
2 Base area of Tank X
= 39 x 29
= 1131 cm
2 Combined base areas of both tanks
= 696 + 1131
= 1827 cm
2 Height of water in Tank W
= 25578 ÷ 1827
= 14 cm
(b)
Decrease in the height of Tank X after some water was poured out
= 3393 ÷ 1131
= 3 cm
Original height of water before some was poured out
= 14 + 2
= 16 cm
Height of water after some was poured out
= 16 - 3
= 13 cm
Height of Tank W
= 2 x 13
= 26 cm
Answer(s): (a) 14 cm; (b) 26 cm