To fill a tank measuring 50 cm by 60 cm by 21 cm completely, it takes Tap A 39 minutes while it takes Tap B only 37 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 9 cubic containers of edges 14 cm, filled to the brim with water are poured into the tank? Leave your answer in minutes and round off to 2 decimal places.
Volume of the tank 
= 50 x 60 x 21
= 63000 cm³
= 63000 mℓ

Volume of 9 containers
= 14 x 14 x 14 x 9
= 24696 cm³ 
= 24696 mℓ

Remaining volume to be filled by the Tap A and Tap B 
= 63000 - 24696
= 38304 mℓ
= 38304 cm³

Fraction of the tank to be filled
= ³⁸³⁰⁴₆₃₀₀₀
= ⁷⁶₁₂₅

Tap A:
1 tank → 39 min
1 min → ¹₃₉ tank

Tap B:
1 tank → 37 min
1 min → ¹₃₇ tank

Tap A and Tap B:
1 min → ¹₃₉ + ¹₃₇ = ³⁷₁₄₄₃ + ³⁹₁₄₄₃ = ⁷⁶₁₄₄₃ tank

1 tank = ¹⁴⁴³₇₆ min

⁷⁶₁₂₅ tank = ¹⁴⁴³₇₆ x ⁷⁶₁₂₅ = ¹⁴⁴³₁₂₅ = 11.544

Answer(s): 11.54 min