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 0.4 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 1.7 m long, 0.1 m wide and 23 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 23
= 920 ℓ
2 u = 920
1 u = 920 ÷ 2 = 460
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 460
= 1380 ℓ
(b)
1 m = 100 cm
1.7 m = 170 cm
0.1 m = 10 cm
Volume of each container
= 170 x 10 x 23
= 39100 cm
3 Volume of water in the tank = 920 ℓ
1 ℓ = 1000 mℓ
920 ℓ = 920000 mℓ
Number of containers needed
= 920000 ÷ 39100
= 23 r 20700
Minimum number of containers needed
= 23 + 1
= 24
Answer(s): (a) 1380 ℓ; (b) 24