Keith is using 12 brown and 8 white tiles to design a section of an outdoor patio for his home. Which ratio compares the number of brown tiles to total number of tiles in the section?

8 : 20

Step-by-step explanation:

This would be 8 : 20 because all together their are 20 tiles and it is only asking for the brown tiles. So you add (the brown tiles) : (overall amount)

10 decreased by 80% is 2.

Since, 20% is left to make 100%, you have to find 20% of 10 which  is 8.

Subtract 8 from 10 and you get 2.

Hope it helps