To fill a tank measuring 50 cm by 30 cm by 40 cm completely, it takes Tap B 6 minutes while it takes Tap C only 14 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 7 cubic containers of edges 10 cm, filled to the brim with water are poured into the tank?
Volume of the tank 
= 50 x 30 x 40
= 60000 cm³

Volume of 7 containers
= 10 x 10 x 10 x 7
= 7000 mℓ

Remaining volume to be filled by the Tap B and Tap C 
= 60000 - 7000
= 53000 mℓ
= 53000 cm³

Fraction of the tank to be filled
= ⁵³⁰⁰⁰₆₀₀₀₀
= ⁵³₆₀

Tap B:
1 tank → 6 min
1 min → ¹₆ tank

Tap C:
1 tank → 14 min
1 min → ¹₁₄ tank

Tap B and Tap C:
1 min → ¹₆ + ¹₁₄ = ⁷₄₂ + ³₄₂ = ⁵₂₁ tank
1 tank → ²¹₅ min

⁵³₆₀ tank → ²¹₅ x ⁵³₆₀ = ³⁷¹₁₀₀ = 3.71 min

Answer(s): 3.71 min