A rectangular tank measuring 160 cm by 70 cm by 120 cm is 50% filled with water. 8 identical bottles 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 50 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 
= 120 x 50%
= 60 cm

Difference in height when 8 bottles were scooped out
= 60 - 40
= 20 cm

Volume of 8 bottles
= 160 x 70 x 20
= 224000 cm³ 

Volume of 1 bottle 
= 224000 ÷ 8
= 28000 mℓ
= 28 ℓ

(b)
Remaining water in the tank 
= 160 x 70 x 40
= 448000 cm³

50 ℓ = 50000 mℓ

Total volume of water to drain
= 448000 + 50000
= 498000 mℓ

10 ℓ = 10000 mℓ

Time taken to drain the water
= 498000 ÷ 10000
= 49.8 min

Answer(s): (a) 28 ℓ; (b) 49.8 min