Water flows into a tank at the rate of 60 ℓ per minute. After 21 min, the tap is turned off and the tank is 0.8 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, 0.2 m wide and 21 cm high. What is the minimum number of containers needed?
(a)
0.8 =
45 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 60 x 21
= 1260 ℓ
4 u = 1260
1 u = 1260 ÷ 4 = 315
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 315
= 315 ℓ
(b)
1 m = 100 cm
1.3 m = 130 cm
0.2 m = 20 cm
Volume of each container
= 130 x 20 x 21
= 54600 cm
3 Volume of water in the tank = 1260 ℓ
1 ℓ = 1000 mℓ
1260 ℓ = 1260000 mℓ
Number of containers needed
= 1260000 ÷ 54600
= 23 r 4200
Minimum number of containers needed
= 23 + 1
= 24
Answer(s): (a) 315 ℓ; (b) 24