# 69 2016 OG problem solving

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Mon Oct 10, 2016 11:26 am

# 69 2016 OG problem solving

by danielheulensen » Thu Jul 13, 2017 11:09 am
didnt like the explanation on this one as well


In a recent election Ms. Robbins received 8000 votes cast by independent voters, that is voters not registered with a specific political party. She also received 10 percent of the votes cast by those voters registered with a political party. IF N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters which of the following represents the number of votes that Ms. Robbins received?

A) 0.06N +3200
B) 0.1N + 7200
C)0.4N + 7200
D)0.1N + 8000
E) 0.06N + 8000

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 Jul 13, 2017 11:30 am
danielheulensen wrote:didnt like the explanation on this one as well


In a recent election Ms. Robbins received 8000 votes cast by independent voters, that is voters not registered with a specific political party. She also received 10 percent of the votes cast by those voters registered with a political party. IF N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters which of the following represents the number of votes that Ms. Robbins received?

A) 0.06N +3200
B) 0.1N + 7200
C)0.4N + 7200
D)0.1N + 8000
E) 0.06N + 8000
Let N = 100,000.

Since 40% of the votes are independent, total independent votes = 40% of 100,000 = 40,000, with the result that total party votes = 100,000 - 40,000 = 60,000.
Since Ms. Robbins receives 10% of the party votes and 8,000 independent votes, total votes for Ms. Robbins = (10% of 60,000) + 8000 = 6000 + 8000 = 14,000.

Since the question stem asks for total number of votes for Ms. Robbins, the target value is 14,000.
Now plug N=100,000 into the answers to see which yields the target value of 14,000.
Only E works:
0.6N + 8000 = (0.6)(100,000) + 8000 = 6000 + 8000 = 14,000.

The correct answer is E.
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

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2621
Joined: Mon Jun 02, 2008 3:17 am
Location: Montreal
Thanked: 1090 times
Followed by:355 members
GMAT Score:780

by Ian Stewart » Thu Jul 13, 2017 12:05 pm
N votes were cast in total

40% were by independent voters, so the rest, 60%, were by voters registered with a party.

So 60% of N, or 0.6N, votes were cast by voters registered with a party.

Ms Robbins received 10% of those votes, so (0.1)*0.6N = 0.06N of those votes. She also received the 8000 votes from independent voters mentioned at the start of the question, for a total of 0.06N + 8000 votes.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com

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 Jul 13, 2017 7:32 pm
Hi danielheulensen,

This question can actually be answered with just a little logic (no real calculations are required).

From the first sentence, we know that Ms. Robbins received 8,000 votes; and from the second sentence, we know she received 10% of the votes from voters registered with a political party. We're told that N is the TOTAL number of votes cast. Since the 10% that were mentioned was NOT 10% of the total votes, the remaining votes that Ms. Robbins received CANNOT be described as .1N (it has to be something LESS than .1N). 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

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 » Fri Jul 14, 2017 4:18 am
In a recent election, Ms. Robbins received 8,000 votes cast by independent voters, that is, voters not registered with a specific political party. She also received 10 percent of the votes cast by those voters registered with a political party. If N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters, which of the following represents the number of votes that Ms. Robbins received?

(A) 0.06N + 3,200
(B) 0.1N + 7,200
(C) 0.4N + 7,200
(D) 0.1N + 8,000
(E) 0.06N + 8,000

OAE
N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters
If 40% of the total voters are independent, then the remaining 60% of the total voters are NOT independent.
In other words, 60% of the total voters (N) are registered voters.
So, the number of registered voters = 0.6N

Ms. Robbins received received 10% of the votes from registered voters
10% of the registered voters = 10% of 0.6N = (0.1)(0.6N) = 0.06N

Ms. Robbins received 8,000 votes cast by independent voters

TOTAL number of votes that Ms. Robbins received = (votes from registered voters) + (votes from independent voters)
= 0.06N + 8,000
= E

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

Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Mon Oct 10, 2016 11:26 am

by danielheulensen » Sat Jul 15, 2017 3:25 pm
Thank you!

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1462
Joined: Thu Apr 09, 2015 9:34 am
Location: New York, NY
Thanked: 39 times
Followed by:22 members

by Jeff@TargetTestPrep » Tue Jul 25, 2017 11:05 am
danielheulensen wrote:didnt like the explanation on this one as well


In a recent election Ms. Robbins received 8000 votes cast by independent voters, that is voters not registered with a specific political party. She also received 10 percent of the votes cast by those voters registered with a political party. IF N is the total number of votes cast in the election and 40 percent of the votes cast were cast by independent voters which of the following represents the number of votes that Ms. Robbins received?

A) 0.06N +3200
B) 0.1N + 7200
C)0.4N + 7200
D)0.1N + 8000
E) 0.06N + 8000
\

We are given that Ms. Robbins received 8,000 votes cast by independent voters and 10% of the votes cast by those who are affiliated with a party.

Since N is the total number of votes and 40% of the votes were cast by independent voters, 60% of the votes were cast by voters affiliated with a party.

Since Ms. Robbins received 10% of the votes cast by those who are affiliated with a party, she received (0.1)(0.6)N = 0.06N of the votes from voters who are affiliated with a party. Since she also received 8,000 votes from independent voters, she received 0.06N + 8,000 total votes.

Answer: E

Jeffrey Miller
Head of GMAT Instruction
[email protected]

Image

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