Water flows into a tank at the rate of 60 ℓ per minute. After 20 min, the tap is turned off and the tank is 0.4 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 1.3 m long, 0.4 m wide and 20 cm high. What is the minimum number of containers needed?
(a)
0.4 =
25 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 60 x 20
= 1200 ℓ
2 u = 1200
1 u = 1200 ÷ 2 = 600
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 600
= 1800 ℓ
(b)
1 m = 100 cm
1.3 m = 130 cm
0.4 m = 40 cm
Volume of each container
= 130 x 40 x 20
= 104000 cm
3 Volume of water in the tank = 1200 ℓ
1 ℓ = 1000 mℓ
1200 ℓ = 1200000 mℓ
Number of containers needed
= 1200000 ÷ 104000
= 11 r 56000
Minimum number of containers needed
= 11 + 1
= 12
Answer(s): (a) 1800 ℓ; (b) 12