A rectangular tank measuring 170 cm by 50 cm by 100 cm is 60% filled with water. 10 identical barrels 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.

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 60%
= 60 cm

Difference in height when 10 barrels were scooped out
= 60 - 40
= 20 cm

Volume of 10 barrels
= 170 x 50 x 20
= 170000 cm³ 

Volume of 1 barrel 
= 170000 ÷ 10
= 17000 mℓ
= 17 ℓ

(b)
Remaining water in the tank 
= 170 x 50 x 40
= 340000 cm³

30 ℓ = 30000 mℓ

Total volume of water to drain
= 340000 + 30000
= 370000 mℓ

10 ℓ = 10000 mℓ

Time taken to drain the water
= 370000 ÷ 10000
= 37 min

Answer(s): (a) 17 ℓ; (b) 37 min