Water flows into a tank at the rate of 30 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 1.6 m long, 0.3 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
= 30 x 10
= 300 ℓ
4 u = 300
1 u = 300 ÷ 4 = 75
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 75
= 75 ℓ
(b)
1 m = 100 cm
1.6 m = 160 cm
0.3 m = 30 cm
Volume of each container
= 160 x 30 x 10
= 48000 cm
3 Volume of water in the tank = 300 ℓ
1 ℓ = 1000 mℓ
300 ℓ = 300000 mℓ
Number of containers needed
= 300000 ÷ 48000
= 6 r 12000
Minimum number of containers needed
= 6 + 1
= 7
Answer(s): (a) 75 ℓ; (b) 7