Water flows into a tank at the rate of 40 ℓ per minute. After 19 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, 0.1 m wide and 19 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
= 40 x 19
= 760 ℓ
2 u = 760
1 u = 760 ÷ 2 = 380
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 380
= 1140 ℓ
(b)
1 m = 100 cm
1.1 m = 110 cm
0.1 m = 10 cm
Volume of each container
= 110 x 10 x 19
= 20900 cm
3 Volume of water in the tank = 760 ℓ
1 ℓ = 1000 mℓ
760 ℓ = 760000 mℓ
Number of containers needed
= 760000 ÷ 20900
= 36 r 7600
Minimum number of containers needed
= 36 + 1
= 37
Answer(s): (a) 1140 ℓ; (b) 37