Question

Jim can choose plan A or plan B for his long distance charges. For each plan, cost (in dollars)depende on minutes used (per month) as shown below.(a)If Jim makes 40 minutes of long distance calls for the month, which plan costs more? How much more does it cost than the other plan?(b) For what number of long distance minutes do the two plans cost the same?

Answer 1

• Plan B, by $4

,

• 140 minutes

Step-by-step explanation:

Part A

From the graph, at 40 minutes, the costs of the plans are:

• Plan A: $4

,

• Plan B: $8

`\begin{gathered} \text{Difference}=8-4 \\ =\$4 \end{gathered}`

Plan B costs more by $4.

Part B

The point where the costs are the same is the time at which the two graphs intersect.

When the number of minutes = 140 minutes

• Cost of Plan A = $14

,

• Cost of Plan B = $14

Thus, the two plans cost the same for 140 minutes of long-distance call.

• If the time spent is less than this amount, Plan B costs more.