To fill a tank measuring 20 cm by 70 cm by 36 cm completely, it takes Tap R 28 minutes while it takes Tap S only 42 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? Leave your answer in minutes and round off to 2 decimal places.
Volume of the tank 
= 20 x 70 x 36
= 50400 cm³
= 50400 mℓ

Volume of 6 containers
= 10 x 10 x 10 x 6
= 6000 cm³ 
= 6000 mℓ

Remaining volume to be filled by the Tap R and Tap S 
= 50400 - 6000
= 44400 mℓ
= 44400 cm³

Fraction of the tank to be filled
= ⁴⁴⁴⁰⁰₅₀₄₀₀
= ³⁷₄₂

Tap R:
1 tank → 28 min
1 min → ¹₂₈ tank

Tap S:
1 tank → 42 min
1 min → ¹₄₂ tank

Tap R and Tap S:
1 min → ¹₂₈ + ¹₄₂ = ³₈₄ + ²₈₄ = ⁵₈₄ tank

1 tank = ⁸⁴₅ min

³⁷₄₂ tank = ⁸⁴₅ x ³⁷₄₂ = ⁷⁴₅ = 14.8

Answer(s): 14.80 min