Water flows into a tank at the rate of 40 ℓ per minute. After 16 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 1.9 m long, 0.1 m wide and 16 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
= 40 x 16
= 640 ℓ
2 u = 640
1 u = 640 ÷ 2 = 320
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 320
= 960 ℓ
(b)
1 m = 100 cm
1.9 m = 190 cm
0.1 m = 10 cm
Volume of each container
= 190 x 10 x 16
= 30400 cm
3 Volume of water in the tank = 640 ℓ
1 ℓ = 1000 mℓ
640 ℓ = 640000 mℓ
Number of containers needed
= 640000 ÷ 30400
= 21 r 1600
Minimum number of containers needed
= 21 + 1
= 22
Answer(s): (a) 960 ℓ; (b) 22