GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Jun 2018, 08:44

Close

GMAT 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 GMAT 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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The cost of a certain phone call was $0.75 for the first 3

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

2 KUDOS received
Manager
Manager
User avatar
Joined: 28 May 2009
Posts: 153
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
GMAT ToolKit User
The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 17 Dec 2013, 17:06
2
7
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

60% (01:01) correct 40% (01:15) wrong based on 621 sessions

HideShow timer Statistics

The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.

_________________

New to GMAT Club? Start here

Kindle Flashcards - Quant (Official Gmat Club, miguemick's Quant topics), and Verbal (Official Gmat Club) - in Kindle (azw3) format

Expert Post
5 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 46128
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 18 Dec 2013, 01:34
5
3
megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.


The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

According to the above the cost for n minutes, where n>3, is \(75 + (n-3)*20=20n+15\) cents. W need to find whether n>15. The cost for 15 minutes is \(20n+15=20*15+15=315\) cents, so we need to find whether the cost is greater than 315 cents.

(1) The cost of the phone call was less than $4.16. Not sufficient.

(2) The cost of the phone call was greater than $3.35. Sufficient.

Answer: B.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Expert Post
2 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 46128
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 18 Dec 2013, 01:39
2
10
Bunuel wrote:
megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.


The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

According to the above the cost for n minutes, where n>3, is \(75 + (n-3)*20=20n+15\) cents. W need to find whether n>15. The cost for 15 minutes is \(20n+15=20*15+15=315\) cents, so we need to find whether the cost is greater than 315 cents.

(1) The cost of the phone call was less than $4.16. Not sufficient.

(2) The cost of the phone call was greater than $3.35. Sufficient.

Answer: B.


Similar questions to practice:
DS:
a-certain-store-sells-chairs-individually-or-in-sets-of-130903.html
a-taxi-company-charges-f-cents-for-the-first-mile-of-the-139875.html
for-each-order-a-certain-company-charges-a-delivery-fee-d-143882.html
for-each-landscaping-job-that-takes-more-than-4-hours-a-85026.html
beth-s-bank-charges-a-service-fee-on-a-regular-checking-89718.html
to-instal-a-cable-television-in-a-home-a-certain-cable-comp-131751.html
the-cost-of-delivery-for-an-order-of-desk-chairs-was-124235.html
for-each-customer-a-bakery-charges-p-dollars-for-the-first-35469.html
a-taxi-company-charges-f-cents-for-the-first-mile-of-the-139875.html
if-bob-produces-36-or-fewer-in-a-week-he-is-paid-x-dollars-88217.html

PS:
to-mail-a-package-the-rate-is-x-cents-for-the-first-pound-144264.html
if-a-taxicab-charges-x-cents-for-the-first-1-9-mile-and-x-97525.html
louie-takes-out-a-three-month-loan-of-1000-the-lender-101506.html
a-certain-telephone-company-offers-two-plans-a-and-b-under-126763.html
a-certain-taxi-company-charges-3-10-for-the-first-1-5-of-a-56649.html
an-auction-house-charges-a-commission-of-15-on-the-first-133397.html
to-mail-a-package-the-rate-is-x-cents-for-the-first-pound-144264.html
at-a-certain-supplier-a-machine-of-type-a-costs-20-000-and-97410.html
for-every-order-a-certain-mail-order-company-charges-a-ship-149154.html
last-month-a-certain-music-club-offered-a-discount-to-134496.html
each-week-harry-is-paid-x-dollars-per-hour-for-the-first-131475.html
a-certain-library-assesses-fines-for-overdue-books-as-follow-127007.html
a-certain-company-retirement-plan-has-a-rule-of-109708.html
according-to-the-table-of-shipping-rates-above-86627.html

Hope it helps.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 22 Feb 2014
Posts: 2
GMAT ToolKit User
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 02 Jul 2014, 08:05
Hi Bunuel,
I tried solving this question by following method and i feel both the statements are not sufficient to get an answer.

given: The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

let's assume phone call lasted for x mins
1) The cost of the phone call was less than $4.16
75+x*20< 416
x<17.04.. Not sufficient as x can be > , < or = 15

2) The cost of the phone call was greater than $3.35
75+x*20>335
x>13 again not sufficient

combining both 13<x<17..not sufficient..
Please let me know where i am going wrong.
Manager
Manager
avatar
Joined: 28 Apr 2014
Posts: 249
GMAT ToolKit User
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 02 Jul 2014, 21:26
varikaur wrote:
Hi Bunuel,
I tried solving this question by following method and i feel both the statements are not sufficient to get an answer.

given: The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

let's assume phone call lasted for x mins
1) The cost of the phone call was less than $4.16
75+x*20< 416
x<17.04.. Not sufficient as x can be > , < or = 15

2) The cost of the phone call was greater than $3.35
75+x*20>335
x>13 again not sufficient

combining both 13<x<17..not sufficient..
Please let me know where i am going wrong.


I get the fallacy mate. The call of 0.20 is after three minutes. So once you as per you calculation get 13 , you have to add the first 3 minutes. Thus you get the total time as 13 + 3 = 16 minutes
1 KUDOS received
Manager
Manager
User avatar
Status: Please do not forget to give kudos if you like my post
Joined: 19 Sep 2008
Posts: 107
Location: United States (CA)
GMAT ToolKit User Premium Member
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 02 Dec 2014, 21:00
1
Lets t = 15 then C = .75 + 12*.20 = 3.15. basically is C > $3.15

1. C < 4.16 not sufficient
2. C > 3.35 so C is definitely greater then 3.15 Sufficient.

Answer: B

megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.

_________________

Please Help with Kudos, if you like my post.


Manager
Manager
User avatar
B
Joined: 28 Sep 2013
Posts: 87
GMAT 1: 740 Q51 V39
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 09 Aug 2016, 18:39
Bunuel wrote:
megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.


The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

According to the above the cost for n minutes, where n>3, is \(75 + (n-3)*20=20n+15\) cents. W need to find whether n>15. The cost for 15 minutes is \(20n+15=20*15+15=315\) cents, so we need to find whether the cost is greater than 315 cents.

(1) The cost of the phone call was less than $4.16. Not sufficient.

(2) The cost of the phone call was greater than $3.35. Sufficient.

Answer: B.


What is the flaw in my reasoning -

0.75X3 + A X 0.2 = Total Cost.

Where A is the # of Minutes after 3 Minutes.

Basically, now we boil down to if A>12

Statement 1 =
0.75X3 + A X 0.2 = 4.16
A = 9.55 Minutes - That means A is not greater than 12. Hence with the calculation we did above we can clearly say that this statement is sufficient to forecast that A is not greater than 12.
_________________

Richa Champion | My GMAT Journey - 470 720 740

Target 760+

Not Improving after Multiple attempts. I can guide You.
Contact me richacrunch2@gmail.com

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 46128
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 10 Aug 2016, 01:06
RichaChampion wrote:
Bunuel wrote:
megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35



While this is a seemingly simple min/max problem, I was wondering if there is a faster way to deal with decimals—as it took me ~4mins to arrive at the solution.


The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

According to the above the cost for n minutes, where n>3, is \(75 + (n-3)*20=20n+15\) cents. W need to find whether n>15. The cost for 15 minutes is \(20n+15=20*15+15=315\) cents, so we need to find whether the cost is greater than 315 cents.

(1) The cost of the phone call was less than $4.16. Not sufficient.

(2) The cost of the phone call was greater than $3.35. Sufficient.

Answer: B.


What is the flaw in my reasoning -

0.75X3 + A X 0.2 = Total Cost.

Where A is the # of Minutes after 3 Minutes.

Basically, now we boil down to if A>12

Statement 1 =
0.75X3 + A X 0.2 = 4.16
A = 9.55 Minutes - That means A is not greater than 12. Hence with the calculation we did above we can clearly say that this statement is sufficient to forecast that A is not greater than 12.


You should read the stem and the solution more carefully.

1. The cost of a certain phone call was $0.75 for the first 3 minutes, not $0.75 for each of the first 3 minutes;
2. A in your solution must be more than 15, not more than 12;
3. (1) says that the cost of the phone call was less than $4.16, not equal to $4.16.

So, it should be 0.75+ A *0.2 < 4.16 --> A < 17.05.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
User avatar
Joined: 05 Apr 2016
Posts: 32
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 05 Sep 2016, 12:03
The trick here is understanding that the 0,75 was for all three minutes (not 0,75 per minute).
Manager
Manager
User avatar
S
Status: Aiming MBA!!
Joined: 19 Aug 2017
Posts: 141
Location: India
GMAT 1: 620 Q49 V25
GPA: 3.75
WE: Web Development (Consulting)
Reviews Badge
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink]

Show Tags

New post 02 Dec 2017, 10:55
megafan wrote:
The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes

(1) The cost of the phone call was less than $4.16
(2) The cost of the phone call was greater than $3.35


For First 3 mins, the cost = 0.75$
For each additional minute after the first 3 minutes, the cost = 0.20$

SO, calculate the cost for the 15 minutes -- cost for first 3 mins + cost for each additional minute after the first 3 minutes
= 0.75$ + 12*0.20$ = 0.75$ + 2.40$ = 3.15$

Now, Question becomes whether the cost of phone call > 3.15$?

1. <4.16$
so the cost can OR cannot be > 3.15$ Insufficient

2. >3.35$
Sufficient. As cost > 3.35$ will always be > than 3.15$.

Answer : B
Re: The cost of a certain phone call was $0.75 for the first 3   [#permalink] 02 Dec 2017, 10:55
Display posts from previous: Sort by

The cost of a certain phone call was $0.75 for the first 3

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.