Tickets to a play cost $5 at the door and $4 in advance. The theater club wants to raise at least $400 from the play. Write and graph an inequality for the number of tickets the theater club needs to sell. If the club sells 40 tickets in advance, how many do they need to sell at the door to reach their goal?

Let us assume the number of tickets sold in advance = x

Let us assume the number of tickets they need to sell at the door = y

Cost of the tickets sold at the door = $5

Cost of the tickets sold in advance = $4

Total amount of money they need to collect = $400

Then

4x + 5y = 400

Now, we already know that the number of tickets sold in advance = 40

Then

(4 * 40) + 5y = 400

160 + 5y = 400

5y = 400 - 160

5y = 240

y = 48

From the above deduction, it can be easily concluded that the number of tickets that they need to sell at the door is 48.