econmics help

[cowgiljl]

Suppose a firm in a perfectly competive industry is producing a output of 10 units. The firms total revenue at this output is $80 and its total cost is $30. The firms marginal cost associated with the 11 unit of a output is $12. What can i say about an increase in production should it produce 11 unit or no

 

this is what i have

output TC MC

10 $30 $3 per unit

11 $42 $12 per unit

 

profit is $50

 

@10 units = 30/10 = $3

@11 unit = 42/11 = $3.80

 

it should not increase production because the cost more per unit to make

 

did i go about this right?

thanks joe