Hmm, great question. If you use equal quantities of yellow and violet, that would mean 6 quarts divided by 2. In this tree we know that there is 3 quarts of yellow paint, while the violet paint is made of blue and red. 1/3 of violet 3 quarts is one US quart, so 1 quart of red paint was used. Then 2/3 of 3 quarts is 2 US quarts, so 2 quarts of blue paint.And because six quarts of brown paint was partially made from 2 quarts of blue paint 2/6=0.33333333333333333(so on) multiplied by 100 to fufill the percentage, 33.333333(so on)%.
So for question number 1, one quart of red paint. Number 2, two quarts of blue paint. Num 3, 33.333333%.
And the 6 quarts of brown paint was made by three quarts of yellow paint, one quart of red paint, and two quarts of blue paint.
Thx 4 the great question