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

Redeem

A shirt that costs k dollars is increased by 30%, then by an

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 1449
Joined: Sat Oct 09, 2010 2:16 pm
Thanked: 59 times
Followed by:33 members

by fskilnik@GMATH » Thu Jan 24, 2019 5:36 am
AAPL wrote:Manhattan Prep

A shirt that costs k dollars is increased by 30%, then by an additional 50%. What is the new price of the shirt in dollars, in terms of k?

A. 0.2k
B. 0.35k
C. 1.15k
D. 1.8k
E. 1.95k
\[k = 100\,\,\,\,\,\mathop \to \limits^{ + \,30\% } \,\,\,\,\,100 + 30 = 130\,\,\,\,\,\mathop \to \limits^{ + \,50\% } \,\,\,\,\,130 + \frac{1}{2}\left( {130} \right) = 195\,\,\,:\,\,\,{\text{TARGET}}\,\,\,\left( {{\text{for}}\,\,k = 100} \right)\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\,\left( {\text{E}} \right)\]

We follow the notations and rationale taught in the GMATH method.

Regards,
Fabio.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Thu Jan 24, 2019 5:40 am
AAPL wrote:A shirt that costs k dollars is increased by 30%, then by an additional 50%. What is the new price of the shirt in dollars, in terms of k?
A. 0.2k
B. 0.35k
C. 1.15k
D. 1.8k
E. 1.95k
OA E
A shirt that costs k dollars is increased by 30%,
So, the new coast = k + (30% of k)
= k + 0.3k
= 1.3k

ASIDE
So, increasing a value by 30% is the same as multiplying that value by 1.3
Similarly, increasing a value by 20% is the same as multiplying that value by 1.2
And increasing a value by 78% is the same as multiplying that value by 1.78
etc

The price is increased by an additional 50%.
New price = (1.5)(1.3k)
= 1.95k

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Thu Jan 24, 2019 9:57 am
Hi All,

We're told that the price of a shirt that costs K dollars is increased by 30%, then that price is increased by an additional 50%. We're asked for the final price of the shirt in dollars, in terms of K. This question can be solved in a number of different ways - including Algebraically and by TESTing VALUES. Based on the answer choices though, you can actually answer this question with just a little logic.

Increasing a value by 30% and then increasing that new overall value by 50% is a concept that's sometimes referred to as "interest on top of interest." In simple terms, it means that the overall increase will be greater than the sum of the two individual increases (since the second increase will be based on the prior increased-value - and not the starting value). Here, that would mean that the overall increase would be GREATER than 30+50 = 80%. There's only one answer that matches...

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Fri Feb 01, 2019 5:20 pm
AAPL wrote:Manhattan Prep

A shirt that costs k dollars is increased by 30%, then by an additional 50%. What is the new price of the shirt in dollars, in terms of k?

A. 0.2k
B. 0.35k
C. 1.15k
D. 1.8k
E. 1.95k

OA E
The new price of the shirt is k x 1.3 x 1.5 = 1.95k.

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Post new topic Post Reply
• Page 1 of 1