Water flows into a tank at the rate of 60 ℓ per minute. After 18 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 1.2 m long, 0.5 m wide and 18 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
= 60 x 18
= 1080 ℓ
4 u = 1080
1 u = 1080 ÷ 4 = 270
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 270
= 270 ℓ
(b)
1 m = 100 cm
1.2 m = 120 cm
0.5 m = 50 cm
Volume of each container
= 120 x 50 x 18
= 108000 cm
3 Volume of water in the tank = 1080 ℓ
1 ℓ = 1000 mℓ
1080 ℓ = 1080000 mℓ
Number of containers needed
= 1080000 ÷ 108000
= 10 r 0
Minimum number of containers needed
= 10 + 1
= 11
Answer(s): (a) 270 ℓ; (b) 11