Water flows into a tank at the rate of 30 ℓ per minute. After 23 min, the tap is turned off and the tank is 0.6 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 1.2 m long, 0.3 m wide and 23 cm high. What is the minimum number of containers needed?
(a)
0.6 =
35 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 30 x 23
= 690 ℓ
3 u = 690
1 u = 690 ÷ 3 = 230
Volume of water to fill the tank to the brim
= 5 u - 3 u
= 2 u
= 2 x 230
= 460 ℓ
(b)
1 m = 100 cm
1.2 m = 120 cm
0.3 m = 30 cm
Volume of each container
= 120 x 30 x 23
= 82800 cm
3 Volume of water in the tank = 690 ℓ
1 ℓ = 1000 mℓ
690 ℓ = 690000 mℓ
Number of containers needed
= 690000 ÷ 82800
= 8 r 27600
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 460 ℓ; (b) 9