The students are doing a fundraiser to help out a friend. They are selling chocolate and cookies for $3 and $2.50 respectively. The cookies were presold to 60 people. At least how many of the chocolates must be sold to collect $255?

At least 18 chocolates sold to collect $225

Step-by-step explanation:

~ Let's say x ⇒ the number of chocolates, y ⇒ the number of cookies ~

1. We can see that the number of chocolates/ cookies * the cost of chocolates/cookies = the total cost of chocolates/cookies. Provided this, it would be that 3x and 2.5y would represent the cost of chocolates and cookies.

2. It is given that there was $225 sold from chocolates and cookies, so we can say that 3x + 2.5y = 225 from this assumption.

3. That being said it is also known that the cookies were sold to 60 people, so we can assume that 60 cookies were sold out, 1 were person. With this information we can see that 3x ⇒ 3 * 60 = 180 ⇒ cost of cookies sold

4. Now we can substitute this value of 3x into the equation 3x + 2.5y = 225, as such: 3x + 2.5y = 225 ⇒ 180 + 2.5y = 225, and now we can solve for y ~

180 + 2.5y = 225,

2.5y = 225 - 180,

2.5y = 45,

y = 45/2.5,

y = At least 18 chocolates sold to collect $225