A flower vendor sells roses for 50 cents each. How much does she pay per flower is she makes $6.00 on every twenty dollars worth sold?

One rose is 50 cents, so 2 roses cost $1 (50 cents x 2).

2 roses per dollar x 20 dollars = 40 total roses sold.

When they sell $20 dollars they make $6, so that means they pay 20-6 = $14 dollars for the 40 roses.

$14 / 40 roses = 0.35 per rose.

She pays 35 cents per rose.