The regular admission price for an amusement park is $72. For a group of 15, or more, the admission price is reduce by $25 per person. How many people need to be in a group to save $500?

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Explanation:

x = number of people

Without the discount, each person pays $72, so the total cost is 72x dollars if x people go through the gate individually.

Now applying the group discount, those x people pay 72-25 = 47 dollars each. Meaning the total cost is now 47x. Keep in mind that in order for the discount to kick in.

Subtracting the two amounts leads to 72x-47x = 25x. It is not a coincidence that we get a coefficient of 25 here.

Set this equal to 500 and solve for x

25x = 500

x = 500/25

x = 20

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If x = 20 people attend individually, then they pay 72*x = 72*20 = 1440 dollars.

If 20 people go as one group, they pay 47x = 47*20 = 940 dollars

We have a savings of 1440-940 = 500 dollars. This confirms the answer.

All 20 people must go as one group if they want to save $500.

5x+2x=49

7x=49

x=7. 35 apples