PSLE There was a total of 30204 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.
- Jade poured 5016 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
= 38 x 33 x 3
= 3762 cm
3 Volume of water in both tanks excluding the water that is 3 cm above that of Tank S
= 30204 - 3762
= 26442 cm
3 Base area of Tank S
= 30 x 26
= 780 cm
2 Base area of Tank T
= 38 x 33
= 1254 cm
2 Combined base areas of both tanks
= 780 + 1254
= 2034 cm
2 Height of water in Tank S
= 26442 ÷ 2034
= 13 cm
(b)
Decrease in the height of Tank T after some water was poured out
= 5016 ÷ 1254
= 4 cm
Original height of water before some was poured out
= 13 + 3
= 16 cm
Height of water after some was poured out
= 16 - 4
= 12 cm
Height of Tank S
= 2 x 12
= 24 cm
Answer(s): (a) 13 cm; (b) 24 cm