Water flows into a tank at the rate of 40 ℓ per minute. After 12 min, the tap is turned off and the tank is 0.8 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 1.8 m long, 0.3 m wide and 12 cm high. What is the minimum number of containers needed?
(a)
0.8 =
45 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 40 x 12
= 480 ℓ
4 u = 480
1 u = 480 ÷ 4 = 120
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 120
= 120 ℓ
(b)
1 m = 100 cm
1.8 m = 180 cm
0.3 m = 30 cm
Volume of each container
= 180 x 30 x 12
= 64800 cm
3 Volume of water in the tank = 480 ℓ
1 ℓ = 1000 mℓ
480 ℓ = 480000 mℓ
Number of containers needed
= 480000 ÷ 64800
= 7 r 26400
Minimum number of containers needed
= 7 + 1
= 8
Answer(s): (a) 120 ℓ; (b) 8