Question

A real estate agent is considering changing her land line phone plan. There are three plans to choose from, all of which involve a monthly service charge of $20. Plan A has a cost of $.39 a minute for daytime calls and $.19 a minute for evening calls. Plan B has a charge of $.49 a minute for daytime calls and $.14 a minute for evening calls. Plan C has a flat rate of $75 with 225 minutes of calls allowed per month and a charge of $.36 per minute beyond that, day or evening.
Required:
a. Determine the total charge under each plan for this case: 120 minutes of day calls and 40 minutes of evening calls in a month.
b. If the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal?
c. Suppose that the agent expects both daytime and evening calls. At what point (i.e., percentage of total call minutes used for daytime calls) would she be indifferent between plans A and B?

Answer 1

Answer:

PLAN A:

(120 * 0.39) + (40 * 0.19) + 20 = $74.40

PLAN B:

(120 * 0.49) + (40 * 0.14) + 20 = $84.40

PLAN C:

$20 + $75 = $95 ;

PLAN A is optimal from 0 to 192 minutes

PLAN C is optimal from 192 minutes onward ;

Explanation:

PLAN A :

Service charge = $20

Daytime = $0.39 per minute

Evening = $0.19 per minute

PLAN B :

Service charge = $20

Daytime = $0.49 per minute

Evening = $0.14 per minute

PLAN C :

Service charge = $20

225 minutes = $75

Minutes beyond 225 = $0.36 per minute

A.)

Determine the total charge under each plan for this case: 120 minutes of day calls and 40 minutes of evening calls in a month.

PLAN A:

(120 * 0.39) + (40 * 0.19) + 20 = $74.40

PLAN B:

(120 * 0.49) + (40 * 0.14) + 20 = $84.40

PLAN C:

$20 + $75 = $95

b. If the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal?

PLAN A:

20 + 0.39D = 95

0.39D = 95 - 20

D = 75 / 0.39

D = 192.31