Water flows into a tank at the rate of 30 ℓ per minute. After 22 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 1.7 m long, 0.4 m wide and 22 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
= 30 x 22
= 660 ℓ
2 u = 660
1 u = 660 ÷ 2 = 330
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 330
= 990 ℓ
(b)
1 m = 100 cm
1.7 m = 170 cm
0.4 m = 40 cm
Volume of each container
= 170 x 40 x 22
= 149600 cm
3 Volume of water in the tank = 660 ℓ
1 ℓ = 1000 mℓ
660 ℓ = 660000 mℓ
Number of containers needed
= 660000 ÷ 149600
= 4 r 61600
Minimum number of containers needed
= 4 + 1
= 5
Answer(s): (a) 990 ℓ; (b) 5