PSLE There was a total of 23670 cm
3 of water in rectangular tanks S and T at first. The height of the water level in tank T was 3 cm above that of tank S.
- Find the height of the water level in tank S.
- Natalie poured 6200 cm3 of water out of tank T. Tank T was then half filled with water. What was the height of tank T?
(a)
Volume of water in Tank T with a height of 3 cm
= 31 x 25 x 3
= 2325 cm
3 Volume of water in both tanks excluding the water that is 3 cm above that of Tank S
= 23670 - 2325
= 21345 cm
3 Base area of Tank S
= 27 x 24
= 648 cm
2 Base area of Tank T
= 31 x 25
= 775 cm
2 Combined base areas of both tanks
= 648 + 775
= 1423 cm
2 Height of water in Tank S
= 21345 ÷ 1423
= 15 cm
(b)
Decrease in the height of Tank T after some water was poured out
= 6200 ÷ 775
= 8 cm
Original height of water before some was poured out
= 15 + 3
= 18 cm
Height of water after some was poured out
= 18 - 8
= 10 cm
Height of Tank S
= 2 x 10
= 20 cm
Answer(s): (a) 15 cm; (b) 20 cm