Water flows into a tank at the rate of 60 ℓ per minute. After 25 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 1.2 m long, 0.4 m wide and 25 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
= 60 x 25
= 1500 ℓ
2 u = 1500
1 u = 1500 ÷ 2 = 750
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 750
= 2250 ℓ
(b)
1 m = 100 cm
1.2 m = 120 cm
0.4 m = 40 cm
Volume of each container
= 120 x 40 x 25
= 120000 cm
3 Volume of water in the tank = 1500 ℓ
1 ℓ = 1000 mℓ
1500 ℓ = 1500000 mℓ
Number of containers needed
= 1500000 ÷ 120000
= 12 r 60000
Minimum number of containers needed
= 12 + 1
= 13
Answer(s): (a) 2250 ℓ; (b) 13