Water flows into a tank at the rate of 40 ℓ per minute. After 10 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 1.5 m long, 0.3 m wide and 10 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 10
= 400 ℓ
2 u = 400
1 u = 400 ÷ 2 = 200
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 200
= 600 ℓ
(b)
1 m = 100 cm
1.5 m = 150 cm
0.3 m = 30 cm
Volume of each container
= 150 x 30 x 10
= 45000 cm
3 Volume of water in the tank = 400 ℓ
1 ℓ = 1000 mℓ
400 ℓ = 400000 mℓ
Number of containers needed
= 400000 ÷ 45000
= 8 r 40000
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 600 ℓ; (b) 9