Water flows into a tank at the rate of 40 ℓ per minute. After 22 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 1.8 m long, 0.4 m wide and 22 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
= 40 x 22
= 880 ℓ
4 u = 880
1 u = 880 ÷ 4 = 220
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 220
= 220 ℓ
(b)
1 m = 100 cm
1.8 m = 180 cm
0.4 m = 40 cm
Volume of each container
= 180 x 40 x 22
= 158400 cm
3 Volume of water in the tank = 880 ℓ
1 ℓ = 1000 mℓ
880 ℓ = 880000 mℓ
Number of containers needed
= 880000 ÷ 158400
= 5 r 88000
Minimum number of containers needed
= 5 + 1
= 6
Answer(s): (a) 220 ℓ; (b) 6