if ballons are on sale at 15 for$3, whats the cost for a ballon? a)50cents b)25cost c)20cents d)20 d

if ballons are on sale at 15 for$3, whats the cost for a ballon? a)50cents b)25cost c)20cents d)20 dollars

Let c be the cost of 1 balloon. We set up a proportion of balloons to cost:
15/3 = 1/c

To solve this proportion for c, we type it in our search engine and we get:
c = 0.2 or 20 cents