GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 03 Aug 2020, 09:30

### 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

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

### Show Tags

17 Dec 2013, 16:06
2
19
00:00

Difficulty:

55% (hard)

Question Stats:

60% (01:38) correct 40% (01:54) wrong based on 696 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.

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 65764
Re: The cost of a certain phone call was $0.75 for the first 3 [#permalink] ### Show Tags 18 Dec 2013, 00:39 2 16 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.

### Show Tags

18 Dec 2013, 00:34
6
5
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.

_________________
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 1 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: 182 Re: The cost of a certain phone call was$0.75 for the first 3  [#permalink]

### Show Tags

02 Jul 2014, 20:26
1
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: 82
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 2 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.

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.
Manager
Joined: 28 Sep 2013
Posts: 79
GMAT 1: 740 Q51 V39
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 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 Math Expert Joined: 02 Sep 2009 Posts: 65764 Re: The cost of a certain phone call was$0.75 for the first 3  [#permalink]

### Show Tags

10 Aug 2016, 00:06
1
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.

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.
_________________
Intern
Joined: 05 Apr 2016
Posts: 24

### 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 Manager Joined: 10 Nov 2018 Posts: 91 Re: The cost of a certain phone call was$0.75 for the first 3  [#permalink]

### Show Tags

23 Jan 2019, 22:44
For a 15 minute call, the call cost will be 3.15 dollars.
A call greater than 15 minutes will have to cost more than 3.15 dollars.

Statement 1 - Not sufficient.
Statement 2 - Sufficient.

Hence B.
Non-Human User
Joined: 09 Sep 2013
Posts: 15594