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

Redeem

starting with 's’

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

starting with 's’

by sanju09 » Tue Nov 10, 2009 1:34 am
The arithmetic mean of the 5 consecutive integers starting with 's' is 'a'. What is the arithmetic mean of 9 consecutive integers that start with s + 2?
A. 2 + s + a
B. 2 + a
C. 2 s
D. 2 a + 2
E. 4 + a
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |
Legendary Member
Posts: 833
Joined: Mon Aug 04, 2008 1:56 am
Thanked: 13 times

by vivek.kapoor83 » Tue Nov 10, 2009 2:27 am
5 consecutive no. will be
s,s+1,s+2,s+3,s+4
adding 5 nos and dividin by 5
(5s+10)/5 = a
s = a-2 .........eq(1)

now, s+2...9 consective integers
adding all 9 will give : 9s+54
AM = (9s+54)/9
AM = s+6
put s = a-2 from eq (1)

AM = a-2+6
AM = a+4
Hence E.
Top
Master | Next Rank: 500 Posts
Posts: 256
Joined: Mon Aug 10, 2009 6:31 pm
Thanked: 3 times

by gmatv09 » Tue Nov 10, 2009 2:54 pm
another approach ...

since we know that the no. of integers in the set is odd..
the avg = middle term
so, s+2 = a or s = a-2

similarly, s+6 = avg of 9 integers
==> a-2+6 = a+4 (E)
Top
Post new topic Post Reply
• Page 1 of 1