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

It is currently 19 Mar 2019, 20:13

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

There was a series of two successive discounts of y% on the price of L

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

Hide Tags

 
Manager
Manager
User avatar
G
Joined: 25 Dec 2018
Posts: 129
Location: India
Concentration: General Management, Finance
GMAT 1: 590 Q48 V23
GPA: 3.4
WE: Engineering (Consulting)
There was a series of two successive discounts of y% on the price of L  [#permalink]

Show Tags

New post 05 Mar 2019, 23:08
1
1
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

91% (02:19) correct 9% (02:08) wrong based on 22 sessions

HideShow timer Statistics

There was a series of two successive discounts of y% on the price of Laptop. The final price of the laptop was tagged at 64% of the original price. What is the value of y?

A) 18%
B) 20%
C) 24%
D) 36%
E) 82%
Manager
Manager
avatar
S
Joined: 12 Apr 2011
Posts: 110
Location: United Arab Emirates
Concentration: Strategy, Marketing
Schools: CBS '21, Yale '21, INSEAD
GMAT 1: 670 Q50 V31
WE: Marketing (Telecommunications)
Re: There was a series of two successive discounts of y% on the price of L  [#permalink]

Show Tags

New post 06 Mar 2019, 11:46
mangamma wrote:
There was a series of two successive discounts of y% on the price of Laptop. The final price of the laptop was tagged at 64% of the original price. What is the value of y?

A) 18%
B) 20%
C) 24%
D) 36%
E) 82%


Let us consider the discount per cent = x%
And the initial price be 100
Hence the discounted price is 64

=> 100 * (1-(x/100))^2 = 64
=> (1-(x/100)) = 64/100= 8/10
=> x/100 = 1-(8/10) = 2/10
=> x = 20%

Hence B is the correct answer.
_________________

Hit Kudos if you like what you see!

Director
Director
User avatar
G
Affiliations: CrackVerbal
Joined: 03 Oct 2013
Posts: 562
Location: India
GMAT 1: 780 Q51 V46
Re: There was a series of two successive discounts of y% on the price of L  [#permalink]

Show Tags

New post 07 Mar 2019, 04:37
1
Top Contributor
Hello,

Greetings for the day!

This is a simple question which can be solved by assuming $100 as the price of the laptop and working backwards to obtain the final price of the laptop as $64.
Since we have to calculate the value of ‘y’, the options should naturally reflect this.

Clearly, options D and E cannot be the answers.

1 discount of 82% will take the price of the laptop much below $64, then where is the question of applying another 82% and getting $64.

A similar thing happens with option D. 36% of 100 is 36. Hence, after the first discount itself, the price reduces to $64. Now, if we apply another 36% discount, the price will not stay at $64, right?

So, options D and E are out of our way.

Now, out of the remaining options, let us pick 20%, because, this is clearly an easy number to deal with, considering the price of the laptop we have assumed.
When we apply the first discount of 20%, 100 becomes 80. When we apply the second discount of 20%, 80 becomes 64. This is clearly what we wanted.

Hence, the answer option is B.

The best approach for answering such questions is a combination of two approaches – eliminate the choices which do not make any sense and subsequently back solve using the answer options provided.

When you are picking options using which to back solve, pick numbers which are easy to deal with. Remember, it’s not a challenge to pick the most difficult option and then work backwards.

Post script: Alternatively, you can use the formula for successive discounts which is [ -a –b + ab/100]%

Hope this helps!
Cheers.
_________________

- CrackVerbal Prep Team

For more info on GMAT and MBA, follow us on @AskCrackVerbal

Register for the Free GMAT Video Training Course : https://www.crackverbal.com/GMAT/online

Veritas Prep GMAT Instructor
User avatar
D
Joined: 16 Oct 2010
Posts: 8989
Location: Pune, India
Re: There was a series of two successive discounts of y% on the price of L  [#permalink]

Show Tags

New post 07 Mar 2019, 07:12
mangamma wrote:
There was a series of two successive discounts of y% on the price of Laptop. The final price of the laptop was tagged at 64% of the original price. What is the value of y?

A) 18%
B) 20%
C) 24%
D) 36%
E) 82%



We know that two successive percentage changes of a% and b% are given by the formula: a + b + ab/100
This is discussed here: https://www.veritasprep.com/blog/2011/0 ... e-changes/

Total percentage change = - y - y + y^2/100 = -36% (since the final price of the laptop is 64% of original)

Note that if y were 18%, the total discount would have been less than 2*18% = 36% due to the impact of the y^2/100 term.

So the value of y must be greater than 18%. 20% seems about right since y^2 term will have a small impact. Let's check.

-20 - 20 + (-20*-20)/100 = -36%

Answer (B)
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 5375
Location: United States (CA)
Re: There was a series of two successive discounts of y% on the price of L  [#permalink]

Show Tags

New post 10 Mar 2019, 19:47
1
mangamma wrote:
There was a series of two successive discounts of y% on the price of Laptop. The final price of the laptop was tagged at 64% of the original price. What is the value of y?

A) 18%
B) 20%
C) 24%
D) 36%
E) 82%


Let p = the original price of the laptop. We can create the equation:

p x (100- y)/100 x (100 - y)/100 = p x 64/100

(100 - y)^2/100^2 = 64/100

Multiplying both sides of the equation by 100^2, we have:

(100 - y)^2 = 64(100)

√[(100 - y)^2] = +/-√6400

100 - y = 80 or 100 - y = -80

y = 20 or y = 180

We ignore y = 180 because an item cannot be discounted more than 100%. Thus, y = 20.

Answer: B
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star 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

GMAT Club Bot
Re: There was a series of two successive discounts of y% on the price of L   [#permalink] 10 Mar 2019, 19:47
Display posts from previous: Sort by

There was a series of two successive discounts of y% on the price of L

  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®.