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

Expert replies

Previous Topic Next Topic

AAPL: Moderator; Posts: 2632; Joined: Sun Oct 29, 2017 2:08 pmFollowed by: 2 members

by AAPL » Thu Jan 24, 2019 5:27 am

Timer

00:00

Answers

Stats

Difficulty—

0% CorrectAvg —

0% IncorrectAvg —

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

Source: Beat The GMAT — Problem Solving | Thu Jan 24, 2019 5:27 am

fskilnik@GMATH: GMAT Instructor; Posts: 1449; Joined: Sat Oct 09, 2010 2:16 pmFollowed by: 33 members; Thanked: 59 times

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

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; 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

GMAT/MBA Expert

[email protected]: Elite Legendary Member; Posts: 10392; Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members; Location: Palo Alto, CA; Thanked: 2867 times; 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]

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8132; Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members; Location: Los Angeles, CA; Thanked: 43 times

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]

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

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review