Cost in dollars a= cupcakes b=cookies. 2a+1.5b a. The cost for one cupcake is $2 and the cost for one cookie is $1.50 b. The total cost for 6 cupcakes and 6 cookies is $21 $2(6)+ $1.50(6)=? $12+$9= $21 c. Is $20 enough to buy 7 cupcakes and 4 cookies? Yes $2(7) + $1.50(4) $14+$6=20 7 cupcakes and 4 cookies cost exactly $20