A telephone company in a town has 500 subscribers on its list and collects fixed charges of Rs 300/- per subscriber per year. The company proposes to increase the annual subscription and it is believed that for every increase of Rs 1/- one subscriber will discontinue the service. Find what increase will bring maximum profit?

We should consider that the organization expands the yearly membership by

   

Along these lines, x is the quantity of supporters who end the administrations.

 

Absolute income,

   

   

   

Separating the two sides w.r.t. x, we get R'(x)

   

For LOCAL maxima and nearby minima, R'(x) = 0

 

   

   

Along these lines, R(x) is most extreme at

   

Along these lines, to get most extreme benefit, the organization should expand its yearly membership by