BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

help required

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 512
Joined: Mon Jun 18, 2012 11:31 pm
Thanked: 42 times
Followed by:20 members

help required

by sana.noor » Mon May 13, 2013 4:58 am
If x is equal to the sum of the even integers from m to n, inclusive, where m and n are positive even integers, which of the following represents the value of x in terms of m and n?
(A) (m+n/2 )(n-m/2 + 1)
(B) 3(m + n)
(C) n^2-m^2/2
(D) 6(m + n)
(E) (m+n/2 )(n-m/2 )

OA is A
Work hard in Silence, Let Success make the noise.

If you found my Post really helpful, then don't forget to click the Thank/follow me button. :)
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 38
Joined: Fri Jan 04, 2013 12:55 am
Thanked: 11 times

by mkdureja » Mon May 13, 2013 5:03 am
Sum of a list of a numbers is Average of the numbers * Number of numbers
In this case, Average = (m+n)/2
Count of numbers = (n-m)/2+1 (As we have to include m and n both)
So, Answer will be: ((m+n)/2)((n-m)/2+1)
Top

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 May 13, 2013 6:42 am
sana.noor wrote:If x is equal to the sum of the even integers from m to n, inclusive, where m and n are positive even integers, which of the following represents the value of x in terms of m and n?
(A) (m+n/2 )(n-m/2 + 1)
(B) 3(m + n)
(C) n^2-m^2/2
(D) 6(m + n)
(E) (m+n/2 )(n-m/2 )

OA is A
sana, when posting rational expressions (fractions), be careful with your notation.
For example, m+n/2 could be read as "m + (n/2)" when, in actuality, you intend it to mean "(m + n)/2"

So, as mkdureja has pointed out, the correct answer is ((m+n)/2)((n-m)/2+1)

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1