The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months. Which of the following represents food purchases, in dollars, for the first 9 months of a year?
A)9y - xy/100
B)9y + xy
C)9y - xy
D)(9y-xy)/9
E)y-xy/6
OA A
Source: Princeton Review
The average American spends y dollars on food per month, exc
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
- GMATGuruNY
- 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
Monthly food expense except in January:BTGmoderatorDC wrote:The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months. Which of the following represents food purchases, in dollars, for the first 9 months of a year?
A)9y - xy/100
B)9y + xy
C)9y - xy
D)(9y-xy)/9
E)y-xy/6
Let y=$2.
Discount in January:
Let x=100%.
Since $2 is spent each month for 8 of the first 9 months, the total spent during these 8 months = 8*2 = 16.
Since food purchases are 100% lower in January -- implying that they are FREE in January -- the amount spent in January = 0.
Total spent = 16+0 = 16.
The correct answer must yield a value of 16 when y=2 and x=100.
Only A works:
9y - (xy/100) = 9*2 - (100*2)/100 = 18-2 = 16.
The correct answer is A.
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
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
- Brent@GMATPrepNow
- 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
This is a Variables in the Answer Choices question (VIAC). This question type can be answered algebraically or using the INPUT-OUTPUT approach.BTGmoderatorDC wrote:The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months. Which of the following represents food purchases, in dollars, for the first 9 months of a year?
A)9y - xy/100
B)9y + xy
C)9y - xy
D)(9y-xy)/9
E)y-xy/6
Mitch has demonstrated the INPUT-OUTPUT approach, so let's solve the question algebraically.
The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months.
In other words, January's food purchase amount is x percent less than y
x percent = x/100
So, x percent of y = (x/100)(y) = xy/100
So, January's food purchase amount = y - xy/100
Which of the following represents food purchases, in dollars, for the first 9 months of a year?
January's food purchase amount = y - xy/100
The food purchase amount for EACH of the other 8 months = y
So, the TOTAL cost = y - xy/100 + y + y + y + y + y + y + y + y
= y - xy/100 + 8y
= 9y - xy/100
Answer: A
Cheers,
Brent
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7247
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
For 8 months, not counting January, the total expenditure for food is 8y.BTGmoderatorDC wrote:The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months. Which of the following represents food purchases, in dollars, for the first 9 months of a year?
A)9y - xy/100
B)9y + xy
C)9y - xy
D)(9y-xy)/9
E)y-xy/6
OA A
Source: Princeton Review
In January, the amount spent on food is (100 - x)/100 * y = (100y - xy)/100
So for the first 9 months, the total expenditure for food is:
8y + (100y - xy)/100
Getting a common denominator,we have:
800y/100 + (100y - xy)/100
(900y - xy)/100 = 900y/100 - xy/100 = 9y - xy/100
Answer: A
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