BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

A telephone company charges x cents for the

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 772
Joined: Wed Aug 30, 2017 6:29 pm
Followed by:6 members

A telephone company charges x cents for the

by BTGmoderatorRO » Sat Feb 17, 2018 11:35 am
A telephone company charges x cents for the first minute of a call and charges for any additional time at the rate of y cents per minute. If a certain call costs $5.55 and lasts more than 1 minute, which of the following expressions represents the length of that call, in minutes?

(A) $$\frac{555-x}{y}$$

(B) $$\frac{555+x-y}{y}$$

(C) $$\frac{555-x+y}{y}$$

(D) $$\frac{555-x-y}{y}$$

(E) $$\frac{555}{x+y}$$

OA is C
How do I tackle this question? I need a simple approach method from an Expert, please. Thanks in anticipation
Top
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 555
Joined: Wed Oct 04, 2017 4:18 pm
Thanked: 180 times
Followed by:12 members

by EconomistGMATTutor » Sun Feb 18, 2018 3:38 am
Roland2rule wrote:A telephone company charges x cents for the first minute of a call and charges for any additional time at the rate of y cents per minute. If a certain call costs $5.55 and lasts more than 1 minute, which of the following expressions represents the length of that call, in minutes?

(A) $$\frac{555-x}{y}$$

(B) $$\frac{555+x-y}{y}$$

(C) $$\frac{555-x+y}{y}$$

(D) $$\frac{555-x-y}{y}$$

(E) $$\frac{555}{x+y}$$

OA is C
How do I tackle this question? I need a simple approach method from an Expert, please. Thanks in anticipation
Hello Roland.

Let's take a look.

Let's suppose that the call lasts t minutes. Now, let's write $5.55 as 555 cents, then

for the first minute = x cents.

for the rest of the call = y(t-1).

Hence, $555 cents = x+y(t-1). This implies $$x+y\left(t-1\right)=555\ \Leftrightarrow\ \ \ yt-y=555-x\ \Leftrightarrow\ \ yt=555-x+y\ \Leftrightarrow\ \ t\ =\ \frac{555-x+y}{y}.$$ This is why the correct answer is the option C.

I hope it helps.

I'm available if you'd like a follow-up.
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.

Image
Top
User avatar
GMAT Instructor
Posts: 1462
Joined: Thu Apr 09, 2015 9:34 am
Location: New York, NY
Thanked: 39 times
Followed by:22 members

by Jeff@TargetTestPrep » Thu Feb 22, 2018 4:56 pm
Roland2rule wrote:A telephone company charges x cents for the first minute of a call and charges for any additional time at the rate of y cents per minute. If a certain call costs $5.55 and lasts more than 1 minute, which of the following expressions represents the length of that call, in minutes?

(A) $$\frac{555-x}{y}$$

(B) $$\frac{555+x-y}{y}$$

(C) $$\frac{555-x+y}{y}$$

(D) $$\frac{555-x-y}{y}$$

(E) $$\frac{555}{x+y}$$
Since x and y are in cents, we should start by expressing $5.55 in cents, which is 555 cents. We can then create the following equation where t = the length of the call in minutes:

555 = x + y(t - 1)

555 - x = yt - y

555 - x + y = yt

(555 - x + y)/y = t

Answer: C

Jeffrey Miller
Head of GMAT Instruction
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
Top
Post new topic Post Reply
• Page 1 of 1