The given equation is
[tex]C=110000+7.5n[/tex]
a)
The number of books=10000
Substitute n=10000 in the given equation, we get
[tex]C=110000+7.5\times10000[/tex][tex]C=185000[/tex]
The total cost is $185,000.
b)
[tex]\text{Average cost =}\frac{185000}{10000}=18.5[/tex]
The average cost of producing 10,000 textbooks is $18.5.
c)
If we need to produce one more after producing 10000 books.
substitute n=10001 in the given equation, we get
[tex]C=110000+7.5(10001)=185007.5[/tex]
[tex]\text{One book cost after printed 10000 book=cost of 10000 books-cost of 10001 books}[/tex]
[tex]\text{One book cost after printed 10000 book=1}85000-185007.5=7.5[/tex]
If you have already produced 10,000 textbooks, it'll cost you $7.5 to produce one more.