Water flows into a tank at the rate of 55 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 1.6 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
= 55 x 20
= 1100 ℓ
2 u = 1100
1 u = 1100 ÷ 2 = 550
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 550
= 1650 ℓ
(b)
1 m = 100 cm
1.6 m = 160 cm
0.4 m = 40 cm
Volume of each container
= 160 x 40 x 20
= 128000 cm
3 Volume of water in the tank = 1100 ℓ
1 ℓ = 1000 mℓ
1100 ℓ = 1100000 mℓ
Number of containers needed
= 1100000 ÷ 128000
= 8 r 76000
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 1650 ℓ; (b) 9