January 15, 2019 January 15, 2019 10:00 PM PST 11:00 PM PST EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299) January 17, 2019 January 17, 2019 08:00 AM PST 09:00 AM PST Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL.
Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 28 May 2009
Posts: 144
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03222013
GPA: 3.57
WE: Information Technology (Consulting)

The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
17 Dec 2013, 16:06
Question Stats:
59% (01:03) correct 41% (01:17) wrong based on 711 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.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
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




Math Expert
Joined: 02 Sep 2009
Posts: 52108

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
18 Dec 2013, 00:39




Math Expert
Joined: 02 Sep 2009
Posts: 52108

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
18 Dec 2013, 00:34
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 minutesAccording to the above the cost for n minutes, where n>3, is \(75 + (n3)*20=20n+15\) 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? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 22 Feb 2014
Posts: 2

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
02 Jul 2014, 07:05
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
Joined: 28 Apr 2014
Posts: 212

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
02 Jul 2014, 20:26
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



Manager
Status: Please do not forget to give kudos if you like my post
Joined: 19 Sep 2008
Posts: 91
Location: United States (CA)

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
02 Dec 2014, 20:00
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
Joined: 28 Sep 2013
Posts: 85

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
09 Aug 2016, 17:39
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 minutesAccording to the above the cost for n minutes, where n>3, is \(75 + (n3)*20=20n+15\) 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



Math Expert
Joined: 02 Sep 2009
Posts: 52108

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
10 Aug 2016, 00:06
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 minutesAccording to the above the cost for n minutes, where n>3, is \(75 + (n3)*20=20n+15\) 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>12Statement 1 = 0.75 X3 + 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? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 05 Apr 2016
Posts: 30

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
05 Sep 2016, 11:03
The trick here is understanding that the 0,75 was for all three minutes (not 0,75 per minute).



Manager
Status: Aiming MBA!!
Joined: 19 Aug 2017
Posts: 110
Location: India
GPA: 3.75
WE: Web Development (Consulting)

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
02 Dec 2017, 09:55
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



NonHuman User
Joined: 09 Sep 2013
Posts: 9400

Re: The cost of a certain phone call was $0.75 for the first 3
[#permalink]
Show Tags
07 Dec 2018, 14:41
Hello from the GMAT Club BumpBot! Thanks to another GMAT 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.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources




Re: The cost of a certain phone call was $0.75 for the first 3 &nbs
[#permalink]
07 Dec 2018, 14:41






