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 0.8 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, 0.5 m wide and 10 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 10
= 400 ℓ
4 u = 400
1 u = 400 ÷ 4 = 100
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 100
= 100 ℓ
(b)
1 m = 100 cm
1.8 m = 180 cm
0.5 m = 50 cm
Volume of each container
= 180 x 50 x 10
= 90000 cm
3 Volume of water in the tank = 400 ℓ
1 ℓ = 1000 mℓ
400 ℓ = 400000 mℓ
Number of containers needed
= 400000 ÷ 90000
= 4 r 40000
Minimum number of containers needed
= 4 + 1
= 5
Answer(s): (a) 100 ℓ; (b) 5