A rectangular tank measuring 150 cm by 50 cm by 110 cm is 40% filled with water. 10 identical jars of water that are completely filled are then scooped out from it. The water level drops to 40 cm. The remaining amount of water in the tank is later poured into a container that contains 30 litres of water. The water is then drained out through a tap found at the bottom of the container at 10 litres per minute.
- What is the capacity of each pail? Answer in litres.
- How long did it take to drain the water from the container completely? Answer in terms of min.
(a)
Original height of water in the tank
= 110 x 40%
= 44 cm
Difference in height when 10 jars were scooped out
= 44 - 40
= 4 cm
Volume of 10 jars
= 150 x 50 x 4
= 30000 cm
3 Volume of 1 jar
= 30000 ÷ 10
= 3000 mℓ
= 3 ℓ
(b)
Remaining water in the tank
= 150 x 50 x 40
= 300000 cm
3 30 ℓ = 30000 mℓ
Total volume of water to drain
= 300000 + 30000
= 330000 mℓ
10 ℓ = 10000 mℓ
Time taken to drain the water
= 330000 ÷ 10000
= 33 min
Answer(s): (a) 3 ℓ; (b) 33 min