Water flows into a tank at the rate of 35 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 1.6 m long, 0.4 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
= 35 x 12
= 420 ℓ
4 u = 420
1 u = 420 ÷ 4 = 105
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 105
= 105 ℓ
(b)
1 m = 100 cm
1.6 m = 160 cm
0.4 m = 40 cm
Volume of each container
= 160 x 40 x 12
= 76800 cm
3 Volume of water in the tank = 420 ℓ
1 ℓ = 1000 mℓ
420 ℓ = 420000 mℓ
Number of containers needed
= 420000 ÷ 76800
= 5 r 36000
Minimum number of containers needed
= 5 + 1
= 6
Answer(s): (a) 105 ℓ; (b) 6