Whats the sum of measures of the interior angles of a pentagon

I'm assuming the question is referring to a regular pentagon where all the sides and angles are equal, because otherwise, I would need more information (such as lengths of sides, meausures of angle, diagram, etc) to be able to solve this.

180(n-2)
n = 5 because a pentagon has 5 sides
5 - 2 = 3
180 * 3 = 540
divide 540 by 5 (again, because a pentagon has 5 sides)
540 ÷ 5 = 108   
The sum of all the interior angles together is 540 degrees, and the measure of just one of them is 108 degrees

So don't take my word i'm not exactly a mathematical person but i would assume a. because while selling the soap every month you increase in sells so you would by 11 percent. the you would get the factor 0.89 which if i had to guess would be the monthly profit over 11 probably wrong tho