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 0.4 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 1.6 m long, 0.1 m wide and 21 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 21
= 1260 ℓ
2 u = 1260
1 u = 1260 ÷ 2 = 630
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 630
= 1890 ℓ
(b)
1 m = 100 cm
1.6 m = 160 cm
0.1 m = 10 cm
Volume of each container
= 160 x 10 x 21
= 33600 cm
3 Volume of water in the tank = 1260 ℓ
1 ℓ = 1000 mℓ
1260 ℓ = 1260000 mℓ
Number of containers needed
= 1260000 ÷ 33600
= 37 r 16800
Minimum number of containers needed
= 37 + 1
= 38
Answer(s): (a) 1890 ℓ; (b) 38