Water flows into a tank at the rate of 40 ℓ per minute. After 24 min, the tap is turned off and the tank is 0.6 filled with water.
- How much more water is needed to fill it to the brim?
- The water in the tank is then poured into containers each 1.5 m long, 0.3 m wide and 24 cm high. What is the minimum number of containers needed?
(a)
0.6 =
35 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 40 x 24
= 960 ℓ
3 u = 960
1 u = 960 ÷ 3 = 320
Volume of water to fill the tank to the brim
= 5 u - 3 u
= 2 u
= 2 x 320
= 640 ℓ
(b)
1 m = 100 cm
1.5 m = 150 cm
0.3 m = 30 cm
Volume of each container
= 150 x 30 x 24
= 108000 cm
3 Volume of water in the tank = 960 ℓ
1 ℓ = 1000 mℓ
960 ℓ = 960000 mℓ
Number of containers needed
= 960000 ÷ 108000
= 8 r 96000
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 640 ℓ; (b) 9