To fill a tank measuring 60 cm by 30 cm by 20 cm completely, it takes Tap U 6 minutes while it takes Tap V only 18 minutes. How long will it take to completely fill the container with water if both the taps are turned on at the same time and 10 cubic containers of edges 6 cm, filled to the brim with water are poured into the tank?
Volume of the tank 
= 60 x 30 x 20
= 36000 cm³

Volume of 10 containers
= 6 x 6 x 6 x 10
= 2160 mℓ

Remaining volume to be filled by the Tap U and Tap V 
= 36000 - 2160
= 33840 mℓ
= 33840 cm³

Fraction of the tank to be filled
= ³³⁸⁴⁰₃₆₀₀₀
= ⁴⁷₅₀

Tap U:
1 tank → 6 min
1 min → ¹₆ tank

Tap V:
1 tank → 18 min
1 min → ¹₁₈ tank

Tap U and Tap V:
1 min → ¹₆ + ¹₁₈ = ³₁₈ + ¹₁₈ = ²₉ tank
1 tank → ⁹₂ min

⁴⁷₅₀ tank → ⁹₂ x ⁴⁷₅₀ = ⁴²³₁₀₀ = 4.23 min

Answer(s): 4.23 min