To fill a tank measuring 60 cm by 50 cm by 40 cm completely, it takes Tap B 8 minutes while it takes Tap C only 12 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 6 cubic containers of edges 10 cm, filled to the brim with water are poured into the tank?
Volume of the tank 
= 60 x 50 x 40
= 120000 cm³

Volume of 6 containers
= 10 x 10 x 10 x 6
= 6000 mℓ

Remaining volume to be filled by the Tap B and Tap C 
= 120000 - 6000
= 114000 mℓ
= 114000 cm³

Fraction of the tank to be filled
= ¹¹⁴⁰⁰⁰₁₂₀₀₀₀
= ¹⁹₂₀

Tap B:
1 tank → 8 min
1 min → ¹₈ tank

Tap C:
1 tank → 12 min
1 min → ¹₁₂ tank

Tap B and Tap C:
1 min → ¹₈ + ¹₁₂ = ³₂₄ + ²₂₄ = ⁵₂₄ tank
1 tank → ²⁴₅ min

¹⁹₂₀ tank → ²⁴₅ x ¹⁹₂₀ = ¹¹⁴₂₅ = 4.56 min

Answer(s): 4.56 min