Answer:
a) [tex]Total Cost=20n+\frac{(\frac{40000}{90}*26)}{n}[/tex]
b) [tex]n=24[/tex]
Step-by-step explanation:
From the question we are told that:
Rate r=90 units per hour
Setup cost =20
Operating Cost =26
Units=40000
Generally the equation for Total cost is mathematically given by
[tex]Total Cost=20n+\frac{(\frac{40000}{90}*26)}{n}[/tex]
[tex]T_n=20n+\frac{11556}{n}\\\\T_n=\frac{20n^2+11556}{n}.....equ 1[/tex]
Differentiating
[tex]T_n'=\frac{n(40n)-(40n^2+11556)}{n_2}\\\\T_n'=\frac{20n^2-11556}{n^2}.....equ 2[/tex]
Equating equ 1 to zero
[tex]0=\frac{20n^2+11556}{n}[/tex]
[tex]n=24[/tex]
Therefore
Substituting n
For Equ 1
[tex]T_n=\frac{20(24)^2+11556}{24}[/tex]
F(n)>0
For Equ 2
[tex]T_n'=\frac{20(24)^2-11556}{24^2}[/tex]
F(n)'<0