Abakery sells a box of 12 cookies for $10.50 and charges $0.24 for each additional cookie. if marshall has $20.00 to buy the box of cookies and additional cookies, what is the maximum number of additional cookies he can buy?

Isabelle is mixing red and blue paint to make purple paint she adds 3/10 of a fluid ounce of red to 12/25 of a fluid ounce of blue to make 1 1/30 fluid ounces of purple how many fluid ounces of red paint ounces of red paint will she need to make 3 fluid ounces of purple paint