A rectangular tank measuring 160 cm by 70 cm by 100 cm is 50% filled with water. 8 identical jars of water that are completely filled are then scooped out from it. The water level drops to 45 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 30 litres per minute.

1. What is the capacity of each pail? Answer in litres.
2. 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 
= 100 x 50%
= 50 cm

Difference in height when 8 jars were scooped out
= 50 - 45
= 5 cm

Volume of 8 jars
= 160 x 70 x 5
= 56000 cm³ 

Volume of 1 jar 
= 56000 ÷ 8
= 7000 mℓ
= 7 ℓ

(b)
Remaining water in the tank 
= 160 x 70 x 45
= 504000 cm³

30 ℓ = 30000 mℓ

Total volume of water to drain
= 504000 + 30000
= 534000 mℓ

30 ℓ = 30000 mℓ

Time taken to drain the water
= 534000 ÷ 30000
= 17.8 min

Answer(s): (a) 7 ℓ; (b) 17.8 min