ticket price is 27 -3(3)= $18 , and Number of people = 40,000+10,000(3)=70,000 .
Explanation:
We start the equation with (27-3x). We don't know how many times we're subtracting $3 from the price. This is multiplied by (40,000+10,000x). 
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This represents the amount of money for tickets multiplied by the amount of people. We still need to add the amount of concessions. Since (40,000+10,000x) represents the number of people, we multiply that by $6.00.This gives us:
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Differentiating this w.r.t x :
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, 
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, { Rounding off }
So, ticket price is 27 -3(3)= $18 , and Number of people = 40,000+10,000(3)=70,000 .