Water flows into a tank at the rate of 60 ℓ per minute. After 21 min, the tap is turned off and the tank is 0.6 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 1.1 m long, 0.1 m wide and 21 cm high. What is the minimum number of containers needed?
(a)
0.6 =
35 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 60 x 21
= 1260 ℓ
3 u = 1260
1 u = 1260 ÷ 3 = 420
Volume of water to fill the tank to the brim
= 5 u - 3 u
= 2 u
= 2 x 420
= 840 ℓ
(b)
1 m = 100 cm
1.1 m = 110 cm
0.1 m = 10 cm
Volume of each container
= 110 x 10 x 21
= 23100 cm
3 Volume of water in the tank = 1260 ℓ
1 ℓ = 1000 mℓ
1260 ℓ = 1260000 mℓ
Number of containers needed
= 1260000 ÷ 23100
= 54 r 12600
Minimum number of containers needed
= 54 + 1
= 55
Answer(s): (a) 840 ℓ; (b) 55