Water flows into a tank at the rate of 40 ℓ per minute. After 23 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, 0.3 m wide and 23 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 23
= 920 ℓ
4 u = 920
1 u = 920 ÷ 4 = 230
Volume of water to fill the tank to the brim
= 5 u - 4 u
= 1 u
= 1 x 230
= 230 ℓ
(b)
1 m = 100 cm
1.4 m = 140 cm
0.3 m = 30 cm
Volume of each container
= 140 x 30 x 23
= 96600 cm
3 Volume of water in the tank = 920 ℓ
1 ℓ = 1000 mℓ
920 ℓ = 920000 mℓ
Number of containers needed
= 920000 ÷ 96600
= 9 r 50600
Minimum number of containers needed
= 9 + 1
= 10
Answer(s): (a) 230 ℓ; (b) 10