Water flows into a tank at the rate of 40 ℓ per minute. After 13 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 1.5 m long, 0.3 m wide and 13 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 13
= 520 ℓ
2 u = 520
1 u = 520 ÷ 2 = 260
Volume of water to fill the tank to the brim
= 5 u - 2 u
= 3 u
= 3 x 260
= 780 ℓ
(b)
1 m = 100 cm
1.5 m = 150 cm
0.3 m = 30 cm
Volume of each container
= 150 x 30 x 13
= 58500 cm
3 Volume of water in the tank = 520 ℓ
1 ℓ = 1000 mℓ
520 ℓ = 520000 mℓ
Number of containers needed
= 520000 ÷ 58500
= 8 r 52000
Minimum number of containers needed
= 8 + 1
= 9
Answer(s): (a) 780 ℓ; (b) 9