May 24 10:00 PM PDT  11:00 PM PDT Join a FREE 1day workshop and learn how to ace the GMAT while keeping your fulltime job. Limited for the first 99 registrants. May 25 07:00 AM PDT  09:00 AM PDT Attend this webinar and master GMAT SC in 10 days by learning how meaning and logic can help you tackle 700+ level SC questions with ease. May 27 01:00 AM PDT  11:59 PM PDT All GMAT Club Tests are free and open on May 27th for Memorial Day! May 27 10:00 PM PDT  11:00 PM PDT Special savings are here for Magoosh GMAT Prep! Even better  save 20% on the plan of your choice, now through midnight on Tuesday, 5/27 May 30 10:00 PM PDT  11:00 PM PDT Application deadlines are just around the corner, so now’s the time to start studying for the GMAT! Start today and save 25% on your GMAT prep. Valid until May 30th.
Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 174

At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
06 Dec 2012, 04:17
Question Stats:
75% (00:58) correct 25% (01:12) wrong based on 1574 sessions
HideShow timer Statistics
At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery? (1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel.
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 55271

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
06 Dec 2012, 04:22
At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?Say the price of a donut is $x and the price of a bagel is $y. We need to find the value of 5x+3y. (1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90 > given that 10x+6y=$12.9 > reduce by 2: 5x+3y=$12.9/2. Sufficient. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel > given that x=y0.15 > 5x+3y=5(y0.15)+3y. We need the value of y (or x). Not sufficient. Answer: A.
_________________




Intern
Joined: 14 Sep 2015
Posts: 9

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
19 Sep 2015, 14:49
I found the answer using both of the statements.
1) 10d + 5b = 12.90 2) d = b  0.15 10(b0.15)+6b=12.90 10b1.5+6b=12.90 16b=14.4 b=0.9 [substitute for b in 2nd equation] d=0.90.15=0.75 5(0.75)+3(0.9)=6.45, which is equal to 12.90(0.5)




VP
Joined: 02 Jul 2012
Posts: 1158
Location: India
Concentration: Strategy
GPA: 3.8
WE: Engineering (Energy and Utilities)

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
06 Dec 2012, 04:23
Question asks for value of 5D + 3B. 1)10D + 6B = 12.9 5D + 3B = 12.9/2. Sufficient 2)We only have D = B  0.15. Even after substitution of this in 5D + 3B we still have an unknown. Insufficient. Answer is A.
_________________



Board of Directors
Joined: 01 Sep 2010
Posts: 3390

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
06 Dec 2012, 04:42
This is a question based on logic you can solve in at most 20 seconds, without any calculation. A clearly is the answer .
_________________



Manager
Joined: 12 Jan 2013
Posts: 145

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
10 Jan 2014, 09:17
Walkabout wrote: At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel. We are given 5*D + 3*B = TC, so what's TC? 1) Look carefully: This simply tells us what 2TC is, so in other words it tells us what 2(5*D + 3*B) is. just take half the result and you've solved the question. 2) This tells us that 5*(B  0.15) + 3*B = TC, but we have two unknowns and one equation, so 2 is not sufficient. We go with A.



Intern
Joined: 10 Jul 2014
Posts: 3

Donut and bagel at bakery question
[#permalink]
Show Tags
10 Jul 2014, 10:10
At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90
(2) At the bakery, the price of a donut is $0.15 less than the price of a bagel.
I understand 1) is sufficient. But I'm not understanding why 2) is insufficient. If you let price of donut be x, then price of bagel is x+0.15. Therefore 10x + 6(x + 0.15) = 12.90. Solve that and get a value for x and obviously x + 0.15.
Am I missing something obvious?



Math Expert
Joined: 02 Sep 2009
Posts: 55271

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
10 Jul 2014, 10:13
JaredL wrote: At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90
(2) At the bakery, the price of a donut is $0.15 less than the price of a bagel.
I understand 1) is sufficient. But I'm not understanding why 2) is insufficient. If you let price of donut be x, then price of bagel is x+0.15. Therefore 10x + 6(x + 0.15) = 12.90. Solve that and get a value for x and obviously x + 0.15.
Am I missing something obvious? Merging similar topics. Please refer to the discussion above. All OG 13 questions with solutions are here: theofficialguidequantitativequestiondirectory143450.htmlP.S. Please read carefully and follow: rulesforpostingpleasereadthisbeforeposting133935.html Pay attention to rules 1, 3, and 7. Thank you.
_________________



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 6231
Location: United States (CA)

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
11 Oct 2016, 16:50
Walkabout wrote: At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel. We are given that all donuts are priced equally and all bagels are priced equally and need to determine the total price of 5 donuts and 3 bagels. Let’s start by defining some variables. D = the price per donut B = the price per bagel Thus we need to determine: 5D + 3B = ? Statement One Alone: At the bakery, the total price of 10 donuts and 6 bagels is $12.90. Using the information in statement one, we can create the following equation: 10D + 6B = 12.90 We can simplify the equation by dividing the entire equation by 2. 5D + 3B = 6.45 Thus, the price for 5 donuts and 3 bagels is $6.45. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E. Statement Two Alone: At the bakery, the price of a donut is $0.15 less than the price of a bagel. We can express D in terms of B: D = B  0.15 Substituting B – 0.15 for D, we get: 5(B – 0.15) + 3B 5B – 0.75 + 3B 8B – 0.75 However, without knowing anything about the price of either D or B, or the total amount spent, we cannot determine the sum of 5D + 3B. Thus, statement two is insufficient. The answer is A.
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button.



Manager
Joined: 11 Jul 2016
Posts: 79

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
20 Nov 2016, 05:48
ScottTargetTestPrep wrote: Walkabout wrote: At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel. We are given that all donuts are priced equally and all bagels are priced equally and need to determine the total price of 5 donuts and 3 bagels. Let’s start by defining some variables. D = the price per donut B = the price per bagel Thus we need to determine: 5D + 3B = ? Statement One Alone: At the bakery, the total price of 10 donuts and 6 bagels is $12.90. Using the information in statement one, we can create the following equation: 10D + 6B = 12.90 We can simplify the equation by dividing the entire equation by 2. 5D + 3B = 6.45 Thus, the price for 5 donuts and 3 bagels is $6.45. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E. Statement Two Alone: At the bakery, the price of a donut is $0.15 less than the price of a bagel. We can express D in terms of B: D = B  0.15 Substituting B – 0.15 for D, we get: 5(B – 0.15) + 3B 5B – 0.75 + 3B 8B – 0.75 However, without knowing anything about the price of either D or B, or the total amount spent, we cannot determine the sum of 5D + 3B. Thus, statement two is insufficient. The answer is A. While I do understand your explanation, I have a different viewpoint.
Its commonly known that if we have two unknowns , we need two equations to solve the Q.
In this Q, from(1) 10x +6y = 12.90 from (2) x = y  0.15
If I see this, the first thing which comes to my mind is option C, ( 2 unknowns x, y and we can solve this with two equations) How to negate this line of thought ?



Manager
Joined: 12 Jun 2016
Posts: 214
Location: India
Concentration: Technology, Leadership
WE: Sales (Telecommunications)

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
29 Jul 2017, 20:19
Hello mqdn, In DS each of the statement has to be checked for sufficiency in Isolation First.. Meaning, when we consider S1 the information in S2 should not be taken in consideration and Vice Versa. We need to Move to consider both statements together only if Each statement by itself is not sufficient. In this question, Since S1 alone is sufficient, we dont even need to check for S1+S2. The correct answer is A. PS: The AD/BCE technique by MGMAT or 12TEN method by Kaplan are both great ways to remember this. mqdn wrote: I found the answer using both of the statements.
1) 10d + 5b = 12.90 2) d = b  0.15 10(b0.15)+6b=12.90 10b1.5+6b=12.90 16b=14.4 b=0.9 [substitute for b in 2nd equation] d=0.90.15=0.75 5(0.75)+3(0.9)=6.45, which is equal to 12.90(0.5)
_________________



Manager
Joined: 12 Jun 2016
Posts: 214
Location: India
Concentration: Technology, Leadership
WE: Sales (Telecommunications)

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
29 Jul 2017, 20:27
Hello Manonamission, My 50 cents here. You are absolutely right  2 unknowns x, y and we can solve this with two equations. But if we look at the question, we dont need value of the two unknown. We need the sum of 5 donuts and 3 Bagels. This or something similar like this (Sum of unknowns) should set off an alarm for us. Maybe, Just MAYBE we dont need two equations to solve this. Probably thats one to avoid falling into the 'C" trap in this question. I hope this helps. Manonamission wrote: ScottTargetTestPrep wrote: Walkabout wrote: At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?
(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90. (2) At the bakery, the price of a donut is $0.15 less than the price of a bagel. We are given that all donuts are priced equally and all bagels are priced equally and need to determine the total price of 5 donuts and 3 bagels. Let’s start by defining some variables. D = the price per donut B = the price per bagel Thus we need to determine: 5D + 3B = ? Statement One Alone: At the bakery, the total price of 10 donuts and 6 bagels is $12.90. Using the information in statement one, we can create the following equation: 10D + 6B = 12.90 We can simplify the equation by dividing the entire equation by 2. 5D + 3B = 6.45 Thus, the price for 5 donuts and 3 bagels is $6.45. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E. Statement Two Alone: At the bakery, the price of a donut is $0.15 less than the price of a bagel. We can express D in terms of B: D = B  0.15 Substituting B – 0.15 for D, we get: 5(B – 0.15) + 3B 5B – 0.75 + 3B 8B – 0.75 However, without knowing anything about the price of either D or B, or the total amount spent, we cannot determine the sum of 5D + 3B. Thus, statement two is insufficient. The answer is A. While I do understand your explanation, I have a different viewpoint.
Its commonly known that if we have two unknowns , we need two equations to solve the Q.
In this Q, from(1) 10x +6y = 12.90 from (2) x = y  0.15
If I see this, the first thing which comes to my mind is option C, ( 2 unknowns x, y and we can solve this with two equations) How to negate this line of thought ?
_________________



NonHuman User
Joined: 09 Sep 2013
Posts: 11009

Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
Show Tags
02 Aug 2018, 00:58
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.
_________________




Re: At a bakery, all donuts are priced equally and all bagels
[#permalink]
02 Aug 2018, 00:58






