PSLE There was a total of 35937 cm
3 of water in rectangular tanks S and T at first. The height of the water level in tank T was 6 cm above that of tank S.
- Find the height of the water level in tank S.
- Rachel poured 6615 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 6 cm
= 35 x 27 x 6
= 5670 cm
3 Volume of water in both tanks excluding the water that is 6 cm above that of Tank S
= 35937 - 5670
= 30267 cm
3 Base area of Tank S
= 27 x 24
= 648 cm
2 Base area of Tank T
= 35 x 27
= 945 cm
2 Combined base areas of both tanks
= 648 + 945
= 1593 cm
2 Height of water in Tank S
= 30267 ÷ 1593
= 19 cm
(b)
Decrease in the height of Tank T after some water was poured out
= 6615 ÷ 945
= 7 cm
Original height of water before some was poured out
= 19 + 6
= 25 cm
Height of water after some was poured out
= 25 - 7
= 18 cm
Height of Tank S
= 2 x 18
= 36 cm
Answer(s): (a) 19 cm; (b) 36 cm