Let's first determine the equation for marginal revenue, R'(q).
[tex]\text{ Revenue = No. of microwaves x Price = \lparen q\rparen\lparen250 - q/40\rparen}[/tex][tex]\text{ R\lparen q\rparen= 250q - }\frac{\text{ q}^2}{40}[/tex][tex]\text{ R'\lparen q\rparen= 250\lparen1\rparen- }\frac{\text{q\lparen2\rparen}}{\text{40}}[/tex][tex]\text{ R'\lparen q\rparen= 250 - }\frac{\text{q}}{20}[/tex]Let's now determine the marginal revenue at q = 1,100.
[tex]\text{ R'\lparen q\rparen= 250 - }\frac{1,100}{20}\text{ = 250 - 55}[/tex][tex]\text{ R'\lparen q\rparen= 195}[/tex]Therefore, R'(1,100) = 195
The answer is 195