Water flows into a tank at the rate of 45 ℓ per minute. After 13 min, the tap is turned off and the tank is 0.6 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 1.2 m long, 0.4 m wide and 13 cm high. What is the minimum number of containers needed?
(a)
0.6 =
35 Let 5 u be the total volume of water when the tank is completely filled.
Volume of water in the tank
= 45 x 13
= 585 ℓ
3 u = 585
1 u = 585 ÷ 3 = 195
Volume of water to fill the tank to the brim
= 5 u - 3 u
= 2 u
= 2 x 195
= 390 ℓ
(b)
1 m = 100 cm
1.2 m = 120 cm
0.4 m = 40 cm
Volume of each container
= 120 x 40 x 13
= 62400 cm
3 Volume of water in the tank = 585 ℓ
1 ℓ = 1000 mℓ
585 ℓ = 585000 mℓ
Number of containers needed
= 585000 ÷ 62400
= 9 r 23400
Minimum number of containers needed
= 9 + 1
= 10
Answer(s): (a) 390 ℓ; (b) 10