Last visit was: 25 Apr 2024, 17:32 It is currently 25 Apr 2024, 17:32

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
User avatar
Retired Moderator
Joined: 07 Jun 2014
Posts: 4810
Own Kudos [?]: 10616 [5]
Given Kudos: 0
GRE 1: Q167 V156
WE:Business Development (Energy and Utilities)
Send PM
Manager
Manager
Joined: 06 Jun 2018
Posts: 102
Own Kudos [?]: 120 [4]
Given Kudos: 4
Send PM
User avatar
Retired Moderator
Joined: 07 Jun 2014
Posts: 4810
Own Kudos [?]: 10616 [3]
Given Kudos: 0
GRE 1: Q167 V156
WE:Business Development (Energy and Utilities)
Send PM
Target Test Prep Representative
Joined: 12 Sep 2018
Status:Founder & CEO, Target Test Prep
Affiliations: Target Test Prep
Posts: 1180
Own Kudos [?]: 5270 [2]
Given Kudos: 5
Send PM
Re: The price of a phone call consists of a standard connection [#permalink]
2
Expert Reply
sandy wrote:
The price of a phone call consists of a standard connection fee, which is constant, plus a per minute charge. A 10-minute call costs $2.90 and a 16-minute call costs $4.40. How much does a 13-minute call cost?

(A) $3.55
(B) $3.57
(C) $3.58
(D) $3.65
(E) $3.77


Letting f = the standard connection fee and n = the per-minute charge, we can create two equations, one for the 10-minute call and one for the 16-minute call::

f + 10n = 2.90

and

f + 16n = 4.40

Subtracting the first equation from the second, we have:

6n = 1.50

n = 0.25 (This is the per-minute charge)

Substituting 0.25 for n into the first equation, we see that f is:

f + 2.5 = 2.90

f = 0.4 (This is the fixed fee)

So a 13-minute call costs 0.4 + 13 x 0.25 = $3.65.

Answer: D
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 11687 [1]
Given Kudos: 136
Send PM
Re: The price of a phone call consists of a standard connection [#permalink]
1
sandy wrote:
The price of a phone call consists of a standard connection fee, which is constant, plus a per minute charge. A 10-minute call costs $2.90 and a 16-minute call costs $4.40. How much does a 13-minute call cost?

(A) $3.55
(B) $3.57
(C) $3.58
(D) $3.65
(E) $3.77


Let C = price of connection fee
Let M = the price PER MINUTE

A 10-minute call costs $2.90
We can write: C + 10M = 2.90

A 16-minute call costs $4.40.
We can write: C + 16M = 4.40

How much does a 13-minute call cost?
So far, we have:
C + 10M = 2.90
C + 16M = 4.40

ONE (slower) approach would be to solve the system for C and M, and then calculate the cost of a 13-minute call.
The FASTER approach is to recognize that something great happens when we ADD the two equations

We get: 2C + 26M = 7.30
Now divide both sides by 2 to get: C + 13M = 3.65

Since C + 13M represents the TOTAL cost of a 13-minute call, we can conclude that a 13-minute call costs $3.65

Answer: D

Cheers,
Brent
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 4424
Own Kudos [?]: 68 [0]
Given Kudos: 0
Send PM
Re: The price of a phone call consists of a standard connection [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
[#permalink]
Moderators:
Moderator
1085 posts
GRE Instructor
218 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne