Water flows into a tank at the rate of 30 ℓ per minute. After 15 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 1.1 m long, 0.2 m wide and 15 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
= 30 x 15
= 450 ℓ
2 u = 450
1 u = 450 ÷ 2 = 225
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 225
= 675 ℓ
(b)
1 m = 100 cm
1.1 m = 110 cm
0.2 m = 20 cm
Volume of each container
= 110 x 20 x 15
= 33000 cm
3 Volume of water in the tank = 450 ℓ
1 ℓ = 1000 mℓ
450 ℓ = 450000 mℓ
Number of containers needed
= 450000 ÷ 33000
= 13 r 21000
Minimum number of containers needed
= 13 + 1
= 14
Answer(s): (a) 675 ℓ; (b) 14