A student want to sell lunches. They will sell the lunches for $4 each. If they had to pay an advertising fee of $20 and the ingredients cost $1.50 to make each lunch, how many potato lunches must they make and sell to make a profit?

They must make lunches of a number greater than 8 to make a profit.

Step-by-step explanation:

Let there be x lunches the student has to make.

So, the selling price of the x lunches will be 4x.

Now, they had to pay an advertising fee of $20 and the ingredients cost $1.5 to make each lunch.

So, the total making charges of x lunches is (20 + 1.5x).

To make a profit the condition is 4x > 20 + 1.5x

⇒ 2.5x > 20

⇒ x > 8.

Therefore, they must make lunches of a number greater than 8 to make a profit. (Answer)