Water flows into a tank at the rate of 50 ℓ per minute. After 18 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 1.7 m long, 0.5 m wide and 18 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
= 50 x 18
= 900 ℓ
2 u = 900
1 u = 900 ÷ 2 = 450
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 450
= 1350 ℓ
(b)
1 m = 100 cm
1.7 m = 170 cm
0.5 m = 50 cm
Volume of each container
= 170 x 50 x 18
= 153000 cm
3 Volume of water in the tank = 900 ℓ
1 ℓ = 1000 mℓ
900 ℓ = 900000 mℓ
Number of containers needed
= 900000 ÷ 153000
= 5 r 135000
Minimum number of containers needed
= 5 + 1
= 6
Answer(s): (a) 1350 ℓ; (b) 6