Water flows into a tank at the rate of 35 ℓ per minute. After 22 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 1.9 m long, 0.2 m wide and 22 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
= 35 x 22
= 770 ℓ
2 u = 770
1 u = 770 ÷ 2 = 385
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 385
= 1155 ℓ
(b)
1 m = 100 cm
1.9 m = 190 cm
0.2 m = 20 cm
Volume of each container
= 190 x 20 x 22
= 83600 cm
3 Volume of water in the tank = 770 ℓ
1 ℓ = 1000 mℓ
770 ℓ = 770000 mℓ
Number of containers needed
= 770000 ÷ 83600
= 9 r 17600
Minimum number of containers needed
= 9 + 1
= 10
Answer(s): (a) 1155 ℓ; (b) 10