Question

n Chatty Cathy’s cell phone plan she pays for minutes used plus a fixed monthly charge. For 500 minutes she pays $35 total, and for 1500 minutes used she pays $55 total. What is her monthly fixed charge?

Answer 1

Find out the what is her monthly fixed charge .

To prove

Let us assume that the cost per mintues = x

Let us assume that the monthly charge be = y

As given

n Chatty Cathy’s cell phone plan she pays for minutes used plus a fixed monthly charge.

For 500 minutes she pays $35 total

Than the equation becomes

500x + y = 35

As given

for 1500 minutes used she pays $55 total.

Than the equation becomes

1500x + y = 55

Subtracted 500x + y = 35 from 1500x + y = 55

1500x - 500x + y - y = 55 - 35

1000x = 20

`x = (20)/(1000)`

x = $0.02

Put in the 500x + y = 35

500 × 0.02 + y = 35

10 + y = 35

y = 35 - 10

y = $25

Therefore the monthly fixed charge be $25.