Trouble translating this word problem

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 5
Joined: Sat Sep 28, 2013 6:37 am

Trouble translating this word problem

by afr114 » Mon Oct 28, 2013 7:02 pm
Three friends sit down to eat 14 slices of Pizza. If two friends eat the same number of slices, and the third friend eats two more slices than each of the other two, how many slices are eaten by the third friend.

Here's my thought process:

Three friends sit down to eat 14 slices of Pizza: A + B + C = 14 Slices

If two friends eat the same number of slices: A = B

the third friend eats two more slices than each of the other two: C = (A+B) + 4
I picked four because it says that the third friend eats two more slices than each of the other two, to me that sounds like two more than A and two more than B, which is 4.

I'm wrong. Would I appreciate help. TYIA.

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 » Mon Oct 28, 2013 8:03 pm
afr114 wrote:Three friends sit down to eat 14 slices of Pizza. If two friends eat the same number of slices, and the third friend eats two more slices than each of the other two, how many slices are eaten by the third friend.

4
6
8
10
12
I've added answer choices, which the GMAT would provide.
We can PLUG IN THE ANSWERS for the number of slices eaten by the 3rd friend.
When the correct answer choice is plugged in, the number eaten by the 3rd friend will be 2 more than the number eaten by each of the other 2 friends.

Answer choice C: 8 slices
Since the remaining 6 slices are split equally by the other 2 friends, the number eaten by each of the other 2 friends = 6/2 = 3.
Difference = 8-3 = 5.
Since the difference is too great, the 3rd friend must eat FEWER slices.
Eliminate C, D and E.

Answer choice B: 6 slices
Since the remaining 8 slices are split equally by the other 2 friends, the number eaten by each of the other 2 friends = 8/2 = 4.
Difference = 6-4 = 2.
Success!

The correct answer is B.
Here's my thought process:

Three friends sit down to eat 14 slices of Pizza: A + B + C = 14 Slices

If two friends eat the same number of slices: A = B

the third friend eats two more slices than each of the other two: C = (A+B) + 4
I picked four because it says that the third friend eats two more slices than each of the other two, to me that sounds like two more than A and two more than B, which is 4.

I'm wrong. Would I appreciate help. TYIA.
The portion in red is incorrect.
C eats 2 more slices than either A or B.
Put another way, A and B each eat 2 fewer slices than C:
A = C-2
B = C-2.

Substituting these equations into A + B + C = 14, we get:
(C-2) + (C-2) + C = 14
3C - 4 = 14
3C = 18
C = 6.
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

User avatar
Master | Next Rank: 500 Posts
Posts: 283
Joined: Sun Jun 23, 2013 11:56 pm
Location: Bangalore, India
Thanked: 97 times
Followed by:26 members
GMAT Score:750

by ganeshrkamath » Mon Oct 28, 2013 8:33 pm
afr114 wrote:Three friends sit down to eat 14 slices of Pizza. If two friends eat the same number of slices, and the third friend eats two more slices than each of the other two, how many slices are eaten by the third friend.

Here's my thought process:

Three friends sit down to eat 14 slices of Pizza: A + B + C = 14 Slices

If two friends eat the same number of slices: A = B

the third friend eats two more slices than each of the other two: C = (A+B) + 4
I picked four because it says that the third friend eats two more slices than each of the other two, to me that sounds like two more than A and two more than B, which is 4.

I'm wrong. Would I appreciate help. TYIA.
The bolded part is where you've gone wrong.

It should be C = A + 2 = B + 2

Had they said "the third friend eats 4 more slices than the other two put together", you would be right.

Solution:
A = B = C - 2
(C-2) + (C-2) + C = 14
3C - 4 = 14
3C = 18
C = 6

Choose B

Cheers
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494

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 » Mon Oct 28, 2013 9:11 pm
afr114 wrote:Three friends sit down to eat 14 slices of Pizza. If two friends eat the same number of slices, and the third friend eats two more slices than each of the other two, how many slices are eaten by the third friend.
One more (slightly different) approach.

Let the number of slices eaten by the first friend = x
So, the number of slices eaten by the second friend = x
And the number of slices eaten by the third friend = x + 2

Total of 14 slices eaten, so x + x + (x + 2) = 14
Simplify: 3x + 2 = 14
Solve: x = 4

Since the third friend ate x + 2 slices, the third friend ate 6 slices.

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