Water flows into a tank at the rate of 45 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 1.3 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
= 45 x 12
= 540 ℓ
4 u = 540
1 u = 540 ÷ 4 = 135
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 135
= 135 ℓ
(b)
1 m = 100 cm
1.3 m = 130 cm
0.3 m = 30 cm
Volume of each container
= 130 x 30 x 12
= 46800 cm
3 Volume of water in the tank = 540 ℓ
1 ℓ = 1000 mℓ
540 ℓ = 540000 mℓ
Number of containers needed
= 540000 ÷ 46800
= 11 r 25200
Minimum number of containers needed
= 11 + 1
= 12
Answer(s): (a) 135 ℓ; (b) 12