Water flows into a tank at the rate of 30 ℓ per minute. After 25 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 1.3 m long, 0.3 m wide and 25 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
= 30 x 25
= 750 ℓ
2 u = 750
1 u = 750 ÷ 2 = 375
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 375
= 1125 ℓ
(b)
1 m = 100 cm
1.3 m = 130 cm
0.3 m = 30 cm
Volume of each container
= 130 x 30 x 25
= 97500 cm
3 Volume of water in the tank = 750 ℓ
1 ℓ = 1000 mℓ
750 ℓ = 750000 mℓ
Number of containers needed
= 750000 ÷ 97500
= 7 r 67500
Minimum number of containers needed
= 7 + 1
= 8
Answer(s): (a) 1125 ℓ; (b) 8