Question

Customers of a phone company can choose between two service plans for long distance calls. The first plan has no monthly fee but charges for each minute of calls. The second plan has a monthly fee and charges an additional for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

Answer 1

Answer:

\\x= P/(c -d)[/tex],

Assume that the price of each minute in the first plan is $c and that the second plan charges a flat rate of $P and a charge  of additional $d for every minute.

Step-by-step explanation

Assume that the price of each minute in the first plan is $c and that the second plan charges a flat rate of $P and a charge  of additional $d for every minute.

Thus, the monthly cost of a customer who consumes x minutes in each plan is:

For the first plan: $cx$

and for the second plan: $P + dx$

Considering that the monthly costs must be the same in each plan, you have to:

$cx = P + dx\\ transposing terms\\cx - dx = P\\ applying common factor\\(c -d)x = P\\ dividing by [tex]c - d$

\\x= P/(c -d)[/tex].

For example if $c = 2; d = 1 y P = 10$, Then the number of minutes would be, $x=10$  and the total cost for each plan would be $20$