Question

sam bought brushes for $8,a palette for $5, and oil paints for $15. He paid $29.82 in all. What sales tax rate did sam pay?

Answer 1

it says brushe(s), and paint(s), in plural, but looks he only got one
maybe they had a get 2 for the price of 1 dunno :P

Answer 2

$$
\text{n% of m is } \cfrac{n}{100}\times m\\
\text{so we know that}\\
\pmatrix{\cfrac{n}{100}\times m} + m = 29.82\\
\text{now we know m = (8+5+15) = 28, so}\\
\pmatrix{\cfrac{n}{100}\times 28} + 28 = 29.82\\
\text{now just solve for "n"}
$$