Question

under ladonnas cellular phone plan, she pays $40 a month for unlimited calls. however, text messages are not included in this monthly fee, and she must pay extra for them. the table shows what ladonnas total monthly cell phone bill would be for various numbers of text messages. what would be the total monthly bill (in dollars) if ladonna used 200 text messages? what is the cost (in dollars) for each text message? if ladonna used 1000 text messages in a month, how much would her bill be?

Explanation:

Step1: Find the cost per text message

The change in bill from 0 to 50 texts: $46 - 40=\$6$.
Number of texts changed: $50 - 0 = 50$.
Cost per text: $\frac{6}{50}=0.12$.

Step2: Find the bill for 200 texts

Base cost is $40$.
Number of texts: 200.
Cost for texts: $200\times0.12 = 24$.
Total bill: $40+24=\$64$.

Step3: Find the bill for 1000 texts

Cost for texts: $1000\times0.12 = 120$.
Total bill: $40 + 120=\$160$.

Answer:

A. $64$
B. $0.12$
C. $160$