BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Problem of discounts to be solved backwards.

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 62
Joined: Mon Aug 02, 2010 3:25 pm
Thanked: 3 times

Problem of discounts to be solved backwards.

by Taniuca » Thu Nov 11, 2010 4:31 pm
I found this problem on the Kaplan. Worth sharing it! answer=$50

At the end of August, a store discounts all swimsuits by 40% to 50%. At the beginning of October, all remaining swimsuits are discounted by an additional 10%. What is the lowest possible original price of a swimsuit that cost $27 in October?
a) $30
b) $45
c) $50
d) $55
e) $60
Top
Source: — Problem Solving |
Legendary Member
Posts: 1119
Joined: Fri May 07, 2010 8:50 am
Thanked: 29 times
Followed by:3 members

by diebeatsthegmat » Thu Nov 11, 2010 6:33 pm
Taniuca wrote:I found this problem on the Kaplan. Worth sharing it! answer=$50

At the end of August, a store discounts all swimsuits by 40% to 50%. At the beginning of October, all remaining swimsuits are discounted by an additional 10%. What is the lowest possible original price of a swimsuit that cost $27 in October?
a) $30
b) $45
c) $50
d) $55
e) $60
is that full problem or sthg was missed?
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Thu Nov 11, 2010 8:36 pm
Taniuca wrote: At the end of August, a store discounts all swimsuits by 40% to 50%. At the beginning of October, all remaining swimsuits are discounted by an additional 10%. What is the lowest possible original price of a swimsuit that cost $27 in October?
a) $30
b) $45
c) $50
d) $55
e) $60
As the question is asking for lowest possible original price, we have to consider the lowest possible discounts are given on that swimsuit. Thus, first discount of 40% and then 10%.

Say, the original price was $100x.
After a discount of 40%, the price is = $60x.
After a discount of 10%, the price is = $54x.

Now, 54x = 27 => x = 0.5.
Therefore, original price = $100x = $100*0.5 = $50

The correct answer is C.
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Master | Next Rank: 500 Posts
Posts: 437
Joined: Sat Nov 22, 2008 5:06 am
Location: India
Thanked: 50 times
Followed by:1 members
GMAT Score:580

by beat_gmat_09 » Thu Nov 11, 2010 8:38 pm
x1 - price after 1st discount.
x2 - original price.

x1(0.9) = 27, x1 = 30.
2 discounts 60% price or 50% price, calculate both and pick the lowest.
x2(0.6) = 30 or x2(0.5)=30.
x2=50 or x2=60.
lowest - 50.

Nice problem.
Hope is the dream of a man awake
Top
User avatar
Legendary Member
Posts: 866
Joined: Mon Aug 02, 2010 6:46 pm
Location: Gwalior, India
Thanked: 31 times

by goyalsau » Thu Nov 11, 2010 8:44 pm
Rahul@gurome wrote:
Taniuca wrote: At the end of August, a store discounts all swimsuits by 40% to 50%. At the beginning of October, all remaining swimsuits are discounted by an additional 10%. What is the lowest possible original price of a swimsuit that cost $27 in October?
a) $30
b) $45
c) $50
d) $55
e) $60
As the question is asking for lowest possible original price, we have to consider the lowest possible discounts are given on that swimsuit. Thus, first discount of 40% and then 10%.

Say, the original price was $100x.
After a discount of 40%, the price is = $60x.
After a discount of 10%, the price is = $54x.

Now, 54x = 27 => x = 0.5.
Therefore, original price = $100x = $100*0.5 = $50

The correct answer is C.
I missed that point and marked E,
Thanks Rahul...
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Thu Nov 11, 2010 8:51 pm
Taniuca wrote:I found this problem on the Kaplan. Worth sharing it! answer=$50

At the end of August, a store discounts all swimsuits by 40% to 50%. At the beginning of October, all remaining swimsuits are discounted by an additional 10%. What is the lowest possible original price of a swimsuit that cost $27 in October?
a) $30
b) $45
c) $50
d) $55
e) $60
We can plug in the answer choices, which represent the lowest possible original price. The correct answer will be a multiple of 10, since the percentages given are multiples of 10 and the final price is an integer. Eliminate B and D. Since we're being asked for the lowest possible original price, we should start with answer choice A, the smallest answer choice, and apply the lowest possible combination of discounts, 40% in August and 10% in October.

Answer choice A: 30
Discounted price in August = 30 - .4(30) = 30-12 = 18. Too small, since the final price in October must be 27.

Answer choice C: 50
Discounted price in August = 50 - .4(50) = 30.
Discounted price in October = 30 - .1(30) = 27. Success!

The correct answer is C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Post new topic Post Reply
• Page 1 of 1