Welcome! Check out our free B-School Guides to learn how you compare with other applicants.

## PR 1024 Functions #6

This topic has 1 expert reply and 4 member replies
CR Just gettin' started!
Joined
15 Mar 2012
Posted:
3 messages
PR 1024 Functions #6 Wed Apr 11, 2012 9:47 am
Elapsed Time: 00:00
• Lap #[LAPCOUNT] ([LAPTIME])
Hi all,

Wondering if someone can help me understand this, its the first Q in this book to stump me..
Page 164
http://books.google.ca/books?id=-9wUwATGS2kC&printsec=frontcover#v=onepage&q&f=true is the digital free look at the Q

f(x) = x^2 + x
f(y) = ?
(1) \$y = 3((\$10)+30)
(2) \$y = \$(\$(4))

Answer is apparently D both sufficient though when looking at the solution it makes absolutely no sense to me... (soln on page 211)

I am convinced this is a book error unless someone can explain why it isnt.

Thanks!!

Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
Shalabh's Quants Really wants to Beat The GMAT!
Joined
06 Apr 2012
Posted:
134 messages
Followed by:
5 members
Thanked:
35 times
Thu Apr 12, 2012 1:04 am
CR wrote:
Hi all,

Wondering if someone can help me understand this, its the first Q in this book to stump me..
Page 164
http://books.google.ca/books?id=-9wUwATGS2kC&printsec=frontcover#v=onepage&q&f=true is the digital free look at the Q

f(x) = x^2 + x
f(y) = ?
(1) \$y = 3((\$10)+30)
(2) \$y = \$(\$(4))

Answer is apparently D both sufficient though when looking at the solution it makes absolutely no sense to me... (soln on page 211)

I am convinced this is a book error unless someone can explain why it isnt.

Thanks!!
can you pl. put down the question?

_________________
Shalabh Jain,
e-GMAT Instructor

CR Just gettin' started!
Joined
15 Mar 2012
Posted:
3 messages
Thu Apr 12, 2012 6:20 am
put down the question? You want me to remove the link?

The question and link to the Q are in the post..

Shalabh's Quants Really wants to Beat The GMAT!
Joined
06 Apr 2012
Posted:
134 messages
Followed by:
5 members
Thanked:
35 times
Thu Apr 12, 2012 7:40 am
CR wrote:
put down the question? You want me to remove the link?

The question and link to the Q are in the post..
No.I mean can you pl. post the question? I cannot access the question via link. I will surely help dear!

_________________
Shalabh Jain,
e-GMAT Instructor

CR Just gettin' started!
Joined
15 Mar 2012
Posted:
3 messages
Thu Apr 12, 2012 9:46 am
The question is in the first post

Its a Data Sufficiency Q, it literally reads as:
F at x = x squared plus x
what is F at y?

f(x) = x^2 + x
f(y) = ?

Scenario 1: weird dollar symbol y = 3 multiplied by ( ( weird dollar symbol 10) plus 30)
Scenario 2: weird dollar symbol y = weird dollar symbol multiplied by ( ( weird dollar symbol multiplied by 4))
(1) \$y = 3((\$10)+30)
(2) \$y = \$(\$(4))

The scenarios don't even follow the same function at x pattern... very odd.

### GMAT/MBA Expert

Stuart Kovinsky GMAT Instructor
Joined
08 Jan 2008
Posted:
3156 messages
Followed by:
461 members
Thanked:
1433 times
GMAT Score:
800
Thu Apr 12, 2012 11:01 am
Hi!

The question makes no sense as you've posted it. Unfortunately, p164 is omitted from that preview of the book, so there's no way to check the actual question.

Here's how the question likely reads in order for (D) to be correct:

If f(x) = x^2 + x for all values of x, what's f(y)?

(1) f(y) = 3(f(10) + 30)
(2) f(y) = f(f(4))

We know that f(x) = x^2 + x for all values of x, accordingly, we know that:

f(y) = y^2 + y

To solve, therefore, we need a value for y or a way to solve for f(y) directly.

(1) f(y) = some ugly equation we can turn into a number (using the function provided) - sufficient.
(2) f(y) = a double application of the function with a number provided, so we can solve - sufficient.

Accordingly, each statement is sufficient alone - choose (D).

_________________
Stuart Kovinsky, B.A. LL.B.
Toronto Office
1-800-KAP-TEST
www.kaptest.com

Free GMAT Practice Test under Proctored Conditions! - Find a practice test near you or live and online in Kaplan's Classroom Anywhere environment. Register today!

### Best Conversation Starters

1 varun289 31 topics
2 sana.noor 23 topics
3 killerdrummer 21 topics
4 Rudy414 19 topics
5 sanaa.rizwan 14 topics
See More Top Beat The GMAT Members...

### Most Active Experts

1 Brent@GMATPrepNow

GMAT Prep Now Teacher

199 posts
2 GMATGuruNY

The Princeton Review Teacher

134 posts
3 Jim@StratusPrep

Stratus Prep

106 posts
4 Anju@Gurome

Gurome

47 posts