Water flows into a tank at the rate of 50 ℓ per minute. After 20 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 1.4 m long, 0.4 m wide and 20 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
= 50 x 20
= 1000 ℓ
4 u = 1000
1 u = 1000 ÷ 4 = 250
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 250
= 250 ℓ
(b)
1 m = 100 cm
1.4 m = 140 cm
0.4 m = 40 cm
Volume of each container
= 140 x 40 x 20
= 112000 cm
3 Volume of water in the tank = 1000 ℓ
1 ℓ = 1000 mℓ
1000 ℓ = 1000000 mℓ
Number of containers needed
= 1000000 ÷ 112000
= 8 r 104000
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 250 ℓ; (b) 9