Answer: For 18 cookies, the cost is 27 dollars.
Explanation:
So we are given that:
a dozen cookies cost $18
And we have to find how many 18 cookies cost. We can solve this problem by finding the ratio, or fraction of dollars per cookie or cookie per dollars.
12 cookies 6 2
---------------- = ----------- = ------------- So this means 2 cookies per 3 dollars.
18 dollars 9 3
Now if you increase the numerator by 9 (the numerator is cookies) and you find that there are 18 cookies, then how much money is there to pay?
This can be found by increasing the denom. by 9 as well:
3 x 9 = 27
So then the cost is 27 dollars, and that is how much you have to pay.