It takes Faucet F 30 minutes to fill a container measuring 20 cm by 8 cm by 16 cm completely while it takes Faucet D only 15 minutes. How long will it take to completely fill the container with water if both faucets are turned on at the same time and 3 cubic cubes of edges 6 cm, filled with water, are poured into the container? Leave the answer in minutes and round off to 2 decimal places.
Time taken by Faucet F to fill the container:

30 min → 1 tank
1 min → ¹₃₀ tank

Time taken by Faucet D to fill the container:
15 min → 1 tank
1 min → ¹₁₅ tank

Volume of the container
= 20 x 8 x 16
= 2560 cm³

Volume of 3 cubic cubes
= 3 x (6 x 6 x 6)
= 648 cm³

Time taken by Faucet F and Faucet D to fill a container:
1 min → ¹₃₀ + ¹₁₅ =³₃₀ = ¹₁₀ container

¹₁₀ container → 1 min
1 container → 1 ÷ ¹₁₀ = 1 x ¹⁰₁ = 10 min

Remaining volume of the container to be filled by both faucets 
= 2560 - 648
= 1912 cm³

Time taken to fill the container
= ¹⁹¹²₂₅₆₀ x 10
= 7.46875
≈ 7.47 min

Answer(s): 7.47 min