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

It is currently 22 Mar 2019, 11:45

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

After her birthday, Fiona had D dollars in gift money.

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

Hide Tags

 
Study Buddy Forum Moderator
User avatar
V
Joined: 04 Sep 2016
Posts: 1305
Location: India
WE: Engineering (Other)
Premium Member
After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 15 Jul 2018, 05:43
2
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

78% (01:40) correct 22% (02:33) wrong based on 110 sessions

HideShow timer Statistics

After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank. If she made no other purchases with that money, then what was the value of D?

A. $240
B. $300
C. $320
D. $360
E. $480

_________________

It's the journey that brings us happiness not the destination.

Feeling stressed, you are not alone!!

Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jun 2018
Posts: 267
Premium Member
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 15 Jul 2018, 06:52
1
adkikani wrote:
After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank. If she made no other purchases with that money, then what was the value of D?

A. $240
B. $300
C. $320
D. $360
E. $480


OA: B

Initial amount =\(D\)
Amount remaining after buying Electric Skateboard =\(D- \frac{3D}{5}\)
Amount remaining after buying movie ticket =\(D- \frac{3D}{5} -\frac{1}{3}\)\((D- \frac{3D}{5})=D*\frac{2}{5}*\frac{2}{3}\)
As per question stem,\(D*\frac{2}{5}*\frac{2}{3}=80\)
\(D=300\)
Study Buddy Forum Moderator
User avatar
V
Joined: 04 Sep 2016
Posts: 1305
Location: India
WE: Engineering (Other)
Premium Member
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 15 Jul 2018, 06:59
Bismarck

Can you please comment on text in RED?

Initial amount =\(D\)
Amount remaining after buying Electric Skateboard =\(D- \frac{3D}{5}\)
OK, I simplified this to get \(\frac{2D}{5}\)

Amount remaining after buying movie ticket =\(D- \frac{3D}{5} -\frac{1}{3}\)\((D- \frac{3D}{5})=D*\frac{2}{5}*\frac{2}{3}\)
I directly multiplied 1/3 *(2D/5) and then took 1-(2D/15) to equate to 80
Where did I go wrong?
_________________

It's the journey that brings us happiness not the destination.

Feeling stressed, you are not alone!!

Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jun 2018
Posts: 267
Premium Member
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 15 Jul 2018, 07:23
1
Can you please comment on text in RED?

Initial amount =\(D\)

Purchase 1
Amount remaining after buying Electric Skateboard =\(D- \frac{3D}{5}\)
OK, I simplified this to get \(\frac{2D}{5}\)
After buying Electric Skateboard,She has now \(\frac{2D}{5}\) remaining with her, instead of \(D\)

Purchase 2
Amount remaining after buying movie ticket =\(D- \frac{3D}{5} -\frac{1}{3}\)\((D- \frac{3D}{5})=D*\frac{2}{5}*\frac{2}{3}\)
I directly multiplied 1/3 *(2D/5) and then took 1-(2D/15) to equate to 80
Where did I go wrong?

Movie ticket price =\(\frac{1}{3} *(\frac{2D}{5})\)
Money remaining after Purchase 2 = Money remaining after Purchase 1 - Movie ticket price =\(\frac{2D}{5}\) - \(\frac{1}{3} *(\frac{2D}{5})\)
Money remaining after Purchase 2\(=\)\(\frac{2D}{5}\) \(-\) \(\frac{1}{3} *(\frac{2D}{5})\)\(=80\)
VP
VP
User avatar
V
Status: It's near - I can see.
Joined: 13 Apr 2013
Posts: 1457
Location: India
Concentration: International Business, Operations
Schools: INSEAD Jan '19
GMAT 1: 480 Q38 V22
GPA: 3.01
WE: Engineering (Real Estate)
Premium Member Reviews Badge
After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 21 Jul 2018, 04:52
adkikani wrote:
After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank. If she made no other purchases with that money, then what was the value of D?

A. $240
B. $300
C. $320
D. $360
E. $480


Answer choices seem easy :

Start with B as it seems easiest to work with:

Say D = $ 300

Expense on skate boards = 3/5 * 300 = $ 180

Balance amount = 300 - 180 = $ 120

Expense on smart card = 1/3 * 120 = $ 40

Total expense = 180 + 40 = $ 220

Amount left to put in the bank = 300 - 220 = $ 80 (perfect match)

(B)
_________________

"Do not watch clock; Do what it does. KEEP GOING."

Intern
Intern
User avatar
B
Joined: 21 Jul 2017
Posts: 12
Location: Germany
Schools: ESADE '21 (A)
GPA: 4
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 13 Aug 2018, 08:02
can somebody explain to me why this approach is incorrect:

I assume that Fiona has in total x dollars.

After the first purchase she is left with 5/3 of x and from this remaining amount she makes a second purchase which is 1/3 of the this amount.

Hence I calculated:

3/5x+1/3(3/5x)+80 = x
--> 9/15x + 3/15x+80 = x
--> 12/15x+80=x
--> 4/5x+80=x
-->80 = 1/5x
--> x = 400

Where is my logical flaw? From the post above it doesn't come clear to me.

Thanks in advance.

Max
CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3516
Location: Canada
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 06 Jan 2019, 09:01
Top Contributor
1
adkikani wrote:
After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank. If she made no other purchases with that money, then what was the value of D?

A. $240
B. $300
C. $320
D. $360
E. $480


One option is to WORK BACKWARDS

The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank.
If she spent 1/3 of her money on a movie passcard, then 2/3 of her money remained (which she put in the bank).
This means 2/3 of her money = $80
We can also say that 1/3 of her money = $40
So, she spent $40 on a movie passcard and saved $80
In other words, at the beginning of that day, she had $120

After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard.
If she spent 3/5 of her money (on a skateboard), then 2/5 of her money remained (to be spent on a movie passcard the following day).
In other words, 2/5 of D = $120
Or we can write: (2/5)D = $120
Multiply both sides by 5 to get: 2D = $600
Divide both sides by 2 to get: D = $300

Answer: B

Cheers,
Brent
_________________

Test confidently with gmatprepnow.com
Image

CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3516
Location: Canada
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 06 Jan 2019, 09:15
Top Contributor
adkikani wrote:
After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank. If she made no other purchases with that money, then what was the value of D?

A. $240
B. $300
C. $320
D. $360
E. $480


Another approach is to use algebra.

After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard.
If Fiona SPENT 3/5 of D dollars, then 2/5 of D dollars REMAINED
In other words, the amount remaining at the end of the day = 2D/5 dollars

The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last $80 in the bank.
If Fiona SPENT 1/3 of her remaining 2D/5 dollars, then she must have SAVED 2/3 of 2D/5 dollars
2/3 of 2D/5 = (2/3)(4D/5) = 4D/15
So, after spending 1/3 of her money that day, 4D/15 dollars remained (which she put in the bank)
In other words, 4D/15 = $80

What was the value of D?
Take: 4D/15 = $80
Multiply both sides by 15 to get: 4D = 1200
Divide both sides by 4 to get: D = $300

Answer: B

Cheers,
Brent
_________________

Test confidently with gmatprepnow.com
Image

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13773
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: After her birthday, Fiona had D dollars in gift money.  [#permalink]

Show Tags

New post 06 Jan 2019, 13:00
Hi All,

We're told that after her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard, then she spent 1/3 of what WAS LEFT on a movie passcard, and then finally put the last $80 in the bank. Assuming she made no other purchases with that money, we're asked for the value of D. This question can be solved in a number of different ways, including by TESTing THE ANSWERS. Based on the given Answers, it looks like Answer B would be the easiest to work with, so let's start there...

Answer B: $300
IF.... D = $300....
Fiona spent (3/5)($300) = $180 on a skateboard, leaving her with $300 - $180 = $120
She then spent (1/3)($120) = $40 on a movie passcard, leaving her with $120 - $40 = $80
This is an exact match for what we were told, so this must be the answer!

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****

GMAT Club Bot
Re: After her birthday, Fiona had D dollars in gift money.   [#permalink] 06 Jan 2019, 13:00
Display posts from previous: Sort by

After her birthday, Fiona had D dollars in gift money.

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


Copyright

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®.