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

Let $x = the cost per flower.

Number of roses sold = 20

Profit on 20 roses = $6

Cost = (30 roses) ($x per rose) = $ 20x

Revenue = ($0.50 per rose) * (20 roses) = $10

Profit = $10 - $ 20x = $6

That is,

10 - 20x = 6

20x = 10 - 6

20x = 4

x = $0.2 = 20 cents

Answer: She paid 20 cents per flower.