Question

I need more math help, the!

Answer 1

Track A takes 20 minutes
Track B takes 15 minutes
In 1 minute track be will do a fraction of 1/20, while track B will do 1/15
Both tracks in a minute = 1/20+1/15
                                      = 35/300
Therefore the two tracks will take 300/35 minutes to fill the 200 cubic feet
That is 300/35
           = 8.57  minutes
           ≈ 9 minutes