Three photographers, Lisa, Mike and Norm, take photos of a w

This topic has expert replies
Moderator
Posts: 7187
Joined: Thu Sep 07, 2017 4:43 pm
Followed by:23 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Three photographers, Lisa, Mike and Norm, take photos of a wedding. The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms. If Norms photos number 10 more than twice the number of Lisa's photos, then how many photos did Norm Take?

A. 40
B. 50
C. 60
D. 80
E. 90

OA E

Source: EMPOWERgmat

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 » Sun Dec 09, 2018 3:48 am
BTGmoderatorDC wrote:Three photographers, Lisa, Mike and Norm, take photos of a wedding. The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms. If Norms photos number 10 more than twice the number of Lisa's photos, then how many photos did Norm Take?

A. 40
B. 50
C. 60
D. 80
E. 90
The sum for Lisa and Mike is 50 less than the sum for Norm and Mike.
Since Mike is common to both sums, the 50-photo difference must be yielded solely by Lisa and Norm.
Implication:
Lisa took 50 fewer photos than Norm.

We can PLUG IN THE ANSWERS, which represent the number of photos taken by Norm.
When the correct answer is plugged in, Norm will take 50 more photos than Lisa.
Let N = Norm and L = Lisa.

D: N=80
Since Norm's total is 10 more than twice Lisa's, we get:
2L = 70.
L = 35.
In this case, N-L = 80-35 = 45.
Since the difference is too small, a greater answer choice is needed.

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: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Sun Dec 09, 2018 3:53 am
BTGmoderatorDC wrote:Three photographers, Lisa, Mike and Norm, take photos of a wedding. The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms. If Norms photos number 10 more than twice the number of Lisa's photos, then how many photos did Norm Take?

A. 40
B. 50
C. 60
D. 80
E. 90

OA E

Source: EMPOWERgmat
Say the number of photos Lisa, Mike and Norm, take are L, M, and N, respectively.

Given the total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms, we have

L + M = M + N - 50
L = N - 50 ---(1)

Given Norms photos number 10 more than twice the number of Lisa's photos, we have

N = 2L + 10 ---(2)

Plugging-in the value of L from eqn (1) in eqn (2), we have

N = 2(N - 50) + 10

N = 90

The correct answer: E

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: Manhattan Review Chennai | Hyderabad | GRE Prep New Delhi | Tarnaka GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

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 » Sun Dec 09, 2018 9:23 am
BTGmoderatorDC wrote:Three photographers, Lisa, Mike and Norm, take photos of a wedding. The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms. If Norms photos number 10 more than twice the number of Lisa's photos, then how many photos did Norm Take?

A. 40
B. 50
C. 60
D. 80
E. 90
We can also solve the question using 1 variable

Norms photos number 10 more than twice the number of Lisa's photos
Let x = the number of photographs that Lisa took.
So, 2x + 10 = the number of photographs that Norm took.

The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms
We can write: (# of Lisa's photos) + (# of Mike's photos) = (# of Mike's photos) + (# of Norm's photos) - 50
Subtract (# of Mike's photos) from both sides to get: (# of Lisa's photos) = (# of Norm's photos) - 50
Plug in pre-defined values to get: (x) = (2x + 10) - 50
Simplify: x = 2x - 40
Solve: x = 40

How many photos did Norm Take?
2x + 10 = the number of photographs that Norm took.
So, 2x + 10 = 2(40) + 10 = 90

Answer: E

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

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7251
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Mon Mar 18, 2019 5:35 pm
BTGmoderatorDC wrote:Three photographers, Lisa, Mike and Norm, take photos of a wedding. The total of Lisa and Mikes photos is 50 less than the sum of Mike's and Norms. If Norms photos number 10 more than twice the number of Lisa's photos, then how many photos did Norm Take?

A. 40
B. 50
C. 60
D. 80
E. 90

OA E

Source: EMPOWERgmat

We can create the equations:

L + M = M + N - 50

L = N - 50

and

N = 10 + 2L

Substituting, we have:

N = 10 + 2(N - 50)

N = 10 + 2N - 100

N = 90

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