Question

You are choosing between two different cell phone plans. The first plan charges a rate of

21 cents per minute. The second plan charges a monthly fee of $44.95 plus 11 cents per
minute. How many minutes would you have to use in a month in order for the second
plan to be preferable?

Answer 1

at least 450 minutes

Explanation:

Find an expression for the cost of each plan as a function of the number of minutes. Set the expressions equal to each other, and solve for the number of minutes.

Let x = number of minutes.

First plan:

cost (in dollars) = 0.21x

Second plan:

cost (in dollars) = 0.11x + 44.95

Set the expressions equal:

0.21x = 0.11x + 44.95

Subtract 0.11x from both sides.

0.1x = 44.95

Divide both sides by 0.1

x = 44.95/0.1

x = 449.5

Since you cannot have a fraction of a minute, the answer is 450 minutes.