Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 29 Jul 2015, 10:26

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Tourist purchased a total of 30 travelers checks in $50 and  Question banks Downloads My Bookmarks Reviews Important topics Author Message TAGS: Intern Joined: 11 Apr 2012 Posts: 42 Followers: 0 Kudos [?]: 20 [0], given: 93 Tourist purchased a total of 30 travelers checks in$50 and [#permalink]  26 Aug 2012, 17:57
4
This post was
BOOKMARKED
00:00

Difficulty:

35% (medium)

Question Stats:

74% (03:29) correct 26% (02:17) wrong based on 238 sessions
Tourist purchased a total of 30 travelers checks in $50 and$100 denominations. The total worth of the travelers checks is $1800. How many checks of$50 denominations can he spend so that average amount (arithmetic mean) of the remaining travelers checks is $80? A. 4 B. 12 C. 15 D. 20 E. 24 [Reveal] Spoiler: OA Senior Manager Joined: 11 May 2011 Posts: 373 Location: US Followers: 3 Kudos [?]: 64 [1] , given: 46 Re: Tourist purchased a total of 30 travellers checks [#permalink] 26 Aug 2012, 18:22 1 This post received KUDOS vinay911 wrote: Tourist purchased a total of 30 travellers checks in$50 and $100 denominations.The total worth of the travelers checks is$1800.How many checks of $50 denominations can he spend so that average amount(arithemetic mean) of the remaining travelers checks is$80?

a)4
b)12
c)15
d)20
e)24

This one took me 2+ min.

x+y = 30
50x+100y=1800
Solving both the equation will give you - x = 24 and y = 6.
Now one can start plug-n-play and can figure out that D fits the answer.
x=4, y=6 makes the average amount of the remaining travelers checks to $80. D wins. _________________ ----------------------------------------------------------------------------------------- What you do TODAY is important because you're exchanging a day of your life for it! ----------------------------------------------------------------------------------------- SVP Joined: 16 Nov 2010 Posts: 1678 Location: United States (IN) Concentration: Strategy, Technology Followers: 31 Kudos [?]: 364 [1] , given: 36 Re: Tourist purchased a total of 30 travellers checks [#permalink] 26 Aug 2012, 18:37 1 This post received KUDOS 1 This post was BOOKMARKED X + y = 30 50x + 100y = 1800 => X +2y = 36 => Y = 6 x = 24 Let n be the number So ((24-n) * 50 + 6*100)/(30-n) = 80 => 120 – 5n + 60 = 240 -8n => 3n = 60 => n = 20 Answer - D _________________ Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant) GMAT Club Premium Membership - big benefits and savings Manager Joined: 24 Jul 2011 Posts: 76 Location: India Concentration: Strategy, General Management GMAT 1: 670 Q49 V33 WE: Asset Management (Manufacturing) Followers: 2 Kudos [?]: 83 [4] , given: 5 Re: Tourist purchased a total of 30 travellers checks [#permalink] 27 Aug 2012, 07:12 4 This post received KUDOS This can be solved easily using algorithm, x + y = 30 ---(i) 50x +100y=1800 => x+2y=36 ---- (ii) Therefore from equation (i) and (ii) we get, y=6 Let, we can use the algorithm to find how 50 and 100 make the average to 80 ................50......................100 ............................80 ...........(100-80)...............(80-50) ..............=20......................=30 >> ............2 .........................3 (this is the ratio by which 50 & 100 are to be combined to make average of 80) >> .............4.........................6 (just multiplying both sides with 2, it does not change the ratio) This means if we have six 100 and four 50 we will get average 80 considering all notes So, extra 50 notes are 24-4= 20 _________________ My mantra for cracking GMAT: Everyone has inborn talent, however those who complement it with hard work we call them 'talented'. +1 Kudos = Thank You Dear Are you saying thank you? GMAT Club Legend Joined: 09 Sep 2013 Posts: 5679 Followers: 321 Kudos [?]: 61 [0], given: 0 Re: Tourist purchased a total of 30 travellers checks [#permalink] 27 Sep 2013, 04:21 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. _________________ Math Expert Joined: 02 Sep 2009 Posts: 28754 Followers: 4583 Kudos [?]: 47245 [0], given: 7115 Re: Tourist purchased a total of 30 travellers checks [#permalink] 27 Sep 2013, 04:28 Expert's post GMATBaumgartner wrote: Tourist purchased a total of 30 travellers checks in$50 and $100 denominations.The total worth of the travelers checks is$1800.How many checks of $50 denominations can he spend so that average amount(arithemetic mean) of the remaining travelers checks is$80?

a)4
b)12
c)15
d)20
e)24

Similar question to practice: a-tourist-purchased-a-total-of-1-500-worth-of-traveler-s-111369.html
_________________
Manager
Joined: 23 Jan 2013
Posts: 174
Concentration: Technology, Other
Schools: Haas
GMAT Date: 01-14-2015
WE: Information Technology (Computer Software)
Followers: 3

Kudos [?]: 31 [0], given: 41

Re: Tourist purchased a total of 30 travellers checks [#permalink]  27 Sep 2013, 06:37
subhashghosh wrote:
X + y = 30
50x + 100y = 1800
=> X +2y = 36
=> Y = 6 x = 24
Let n be the number
So ((24-n) * 50 + 6*100)/(30-n) = 80

=> 120 – 5n + 60 = 240 -8n
=> 3n = 60
=> n = 20

I am confused as to why cant we do the opposite for this

(24*50 + (6-n)*100)/(30-n)) = 80 ?
The answer doesnt hold then ....
Intern
Joined: 06 Sep 2013
Posts: 16
Followers: 0

Kudos [?]: 6 [0], given: 3

Re: Tourist purchased a total of 30 travellers checks [#permalink]  27 Sep 2013, 06:59
GMATBaumgartner wrote:
Tourist purchased a total of 30 travellers checks in $50 and$100 denominations.The total worth of the travelers checks is $1800.How many checks of$50 denominations can he spend so that average amount(arithemetic mean) of the remaining travelers checks is $80? a)4 b)12 c)15 d)20 e)24 actually there is no need to calculate the numbers of two checks. Here is how I got the correct answer: say the number of checks need to be spent to get the final average amount of$80 is x
Average amount= amount of $100 checks / numbers of remaining checks then 1800-50*x / 30-x =80 x= 20 Director Status: 1,750 Q's attempted and counting Affiliations: University of Florida Joined: 09 Jul 2013 Posts: 514 Location: United States (FL) Schools: UFL (A) GMAT 1: 600 Q45 V29 GMAT 2: 590 Q35 V35 GMAT 3: 570 Q42 V28 GMAT 4: 610 Q44 V30 GPA: 3.45 WE: Accounting (Accounting) Followers: 24 Kudos [?]: 437 [0], given: 630 Re: Tourist purchased a total of 30 travelers checks in$50 and [#permalink]  01 Dec 2013, 22:08
you could set-up a quick table and brute force the answer.

A 4 * 50 200 1800 -200 1600 26 61.54
B 12 * 50 600 1800 -600 1200 18 66.67
C 15 * 50 750 1800 -750 1050 15 70.00
D 20 * 50 1000 1800 -1000 800 10 80.00
E 24 * 50 1200 1800 -1200 600 6 100.00
_________________

Got Kudos? Tis better to give than receive | ANALYSIS OF MOST DIFFICULT QUESTION TYPES
Need motivation? check out this video or this one | "We are what we repeatedly do. Excellence, then, is not an act, but a habit." - Aristotle
100 HARDEST CR QUESTIONS | 100 HARDEST SC QUESTIONS | 100 HARDEST PS QUESTIONS| 25 HARDEST QUESTIONS | 225 RC PASSAGES W/ TIMER!!!
PS QUESTION DIRECTORY|DS QUESTION DIRECTORY | SC QUESTION DIRECTORY | CR QUESTION DIRECTORY | RC QUESTION DIRECTORY

BEST OVERALL QUANT BOOK FOR THE MONEY | MAXIMIZE YOUR STUDY TIME

Manager
Joined: 21 Oct 2013
Posts: 194
Location: Germany
GMAT 1: 660 Q45 V36
GPA: 3.51
Followers: 0

Kudos [?]: 22 [0], given: 19

Re: Tourist purchased a total of 30 travelers checks in $50 and [#permalink] 10 Mar 2014, 07:18 average is 80$, only pssible total amount for this is 800 $. Hence he can spend 1000$ which equals to 20 50$checks. Answer D. Manager Joined: 17 Mar 2014 Posts: 93 Followers: 0 Kudos [?]: 32 [0], given: 194 Re: Tourist purchased a total of 30 travelers checks in$50 and [#permalink]  24 Oct 2014, 11:03
GMATBaumgartner wrote:
Tourist purchased a total of 30 travelers checks in $50 and$100 denominations. The total worth of the travelers checks is $1800. How many checks of$50 denominations can he spend so that average amount (arithmetic mean) of the remaining travelers checks is $80? A. 4 B. 12 C. 15 D. 20 E. 24 I took more than 2min to solve this question. Is there any quick way? My approach was this. Initially, Tourist had total 30 travelers checks. Let say say, he initially had x number of$50 travelers checks. So he will have 30-x number of $100 travelers checks. The total worth of the travelers checks is$1800.

x*50 + (30-x)*100 = 1800
x*5+(30-x)*10=180
300-x*5=180
x=24

So he had 24 fifty dollar travelers checks and (30-24=6) hundred dollar travelers checks.

Suppose he spends few checks, remaining number of $50 is y (5*y+6*100)/(y+6) = 80 ----comments:- Weight Average Mean Formula. He did not spend any$100 checks so 6 is as it is.
y=4

he was left with only 4 checks of $50. So he spent 20 checks of$ 50.

Verbal Forum Moderator
Joined: 29 Apr 2015
Posts: 544
Followers: 9

Kudos [?]: 288 [0], given: 221

Re: Tourist purchased a total of 30 travelers checks in $50 and [#permalink] 06 May 2015, 13:04 ammuseeru wrote: GMATBaumgartner wrote: Tourist purchased a total of 30 travelers checks in$50 and $100 denominations. The total worth of the travelers checks is$1800. How many checks of $50 denominations can he spend so that average amount (arithmetic mean) of the remaining travelers checks is$80?

A. 4
B. 12
C. 15
D. 20
E. 24

I took more than 2min to solve this question. Is there any quick way?

Initially, Tourist had total 30 travelers checks.
Let say say, he initially had x number of $50 travelers checks. So he will have 30-x number of$100 travelers checks.
The total worth of the travelers checks is $1800. x*50 + (30-x)*100 = 1800 x*5+(30-x)*10=180 300-x*5=180 x=24 So he had 24 fifty dollar travelers checks and (30-24=6) hundred dollar travelers checks. Suppose he spends few checks, remaining number of$50 is y

(5*y+6*100)/(y+6) = 80 ----comments:- Weight Average Mean Formula. He did not spend any $100 checks so 6 is as it is. y=4 he was left with only 4 checks of$50. So he spent 20 checks of $50. Answer is D I Also had 2+ minutes until i figured out, that it might be the best way to start plugging in. Start in the middle with plugging in and check if the answer fits the average ov$80.
Start Plugging in 15 and you get 15*50 = 750 spent leaving 1050 USD and 15 tickets averaging $70 > eliminate this answer choice. If youre not sure which way to go, choose one direction, plug in 20 and you get 20*50 = 1000 spent leaving 800 USD and 20 tickets averaging$80.

Very easy, but it took me more than 5min to figure out which method to take ... poor me
_________________

Help a KUDOS addict by clicking +1 Kudos and make me happy

PS Please send me PM if I do not respond to your question within 24 hours.

Intern
Joined: 20 Oct 2014
Posts: 4
Followers: 0

Kudos [?]: 0 [0], given: 20

Re: Tourist purchased a total of 30 travelers checks in $50 and [#permalink] 07 May 2015, 02:36 Tourist purchased a total of 30 travelers checks in$50 and $100 denominations. The total worth of the travelers checks is$1800. How many checks of $50 denominations can he spend so that average amount (arithmetic mean) of the remaining travelers checks is$80?

A. 4
B. 12
C. 15
D. 20
E. 24

let x be the number of $50 checks he had to start with. 50x + 100(30-x) = 1800 Solving, we get x=24 therefore he had 6$100 checks (value $600) After he spends some$50 checks, let y be the total number of checks he has remaining.
Therefore,
80y = 6*100 + 50(y-6) ....... eqauting the value of the checks
we get y=10
Hence we had 10 total checks remaining, out of which 6 were $100 and 4$50.
Therefore, he spend 20 $50 checks. Re: Tourist purchased a total of 30 travelers checks in$50 and   [#permalink] 07 May 2015, 02:36
Similar topics Replies Last post
Similar
Topics:
4 Jack purchased two chairs at a discount of 50% 2 07 May 2014, 05:34
5 Micheal purchased a total of $1,200 worth of traveler’s chec 5 26 Jul 2013, 22:31 4 In the county of Veenapaniville, there are a total of 50 7 27 Aug 2012, 21:07 5 A tourist purchased a total of$1,500 worth of traveler’s 7 23 Mar 2011, 10:37
4 Advance purchase discounts for airline travel 6 05 Oct 2009, 22:05
Display posts from previous: Sort by