GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Jan 2019, 12:16

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
• ### Free GMAT Number Properties Webinar

January 27, 2019

January 27, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.

# What is the average of all integers from 1 to 100 that end in 2?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52431
What is the average of all integers from 1 to 100 that end in 2?  [#permalink]

### Show Tags

28 Feb 2018, 23:52
00:00

Difficulty:

25% (medium)

Question Stats:

83% (01:07) correct 18% (01:08) wrong based on 62 sessions

### HideShow timer Statistics

What is the average of all integers from 1 to 100 that end in 2?

(A) 46

(B) 47

(C) 48

(D) 50

(E) None of these

_________________
Senior PS Moderator
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12
What is the average of all integers from 1 to 100 that end in 2?  [#permalink]

### Show Tags

28 Feb 2018, 23:58
Bunuel wrote:
What is the average of all integers from 1 to 100 that end in 2?

(A) 46

(B) 47

(C) 48

(D) 50

(E) None of these

The integers which end in 2 from 1 to 100 are 2,12,22,32,42,52,62,72,82,92

The average of these numbers is the average of the middle 2 terms
,since the elements are in an AP and are even in number

Therefore, the average is $$\frac{42+52}{2} = \frac{94}{2} = 47$$(Option B)

_________________

You've got what it takes, but it will take everything you've got

examPAL Representative
Joined: 07 Dec 2017
Posts: 868
Re: What is the average of all integers from 1 to 100 that end in 2?  [#permalink]

### Show Tags

28 Feb 2018, 23:58
Bunuel wrote:
What is the average of all integers from 1 to 100 that end in 2?

(A) 46

(B) 47

(C) 48

(D) 50

(E) None of these

Instead of exlplicitly calculating, we'll use the logic of arithmetic series.
This is a Logcial approach.

We're asked to find the average of 2,12,12,....82,92.
We can pair these off into 2 + 92, 12 + 82, ... 42 + 52, each of which sum to 94.
Since each pair has an average of 94/2 = 47, so does the total sum.

_________________

Crack the GMAT with the complete 2019 bundle:

Online course + Boot camp training + GMAT Club tests + Unlimited support and save 25% on any GMAT course!

Valid until Jan 31st at 23:55 PST.

Choose my course

Manager
Joined: 23 Sep 2016
Posts: 214
Re: What is the average of all integers from 1 to 100 that end in 2?  [#permalink]

### Show Tags

03 Mar 2018, 03:12
Bunuel wrote:
What is the average of all integers from 1 to 100 that end in 2?

(A) 46

(B) 47

(C) 48

(D) 50

(E) None of these

IMO B
number that lie between 1-100 and ends with 2 are 2,12,22.....so on
there are 10 number so total =n*(a+l)/2(n= number of terms, a=1st term, and l= last term)
10*(2+92)/2 =5*94
average = 5*94/10=47
Senior SC Moderator
Joined: 22 May 2016
Posts: 2373
What is the average of all integers from 1 to 100 that end in 2?  [#permalink]

### Show Tags

03 Mar 2018, 14:12
1
Bunuel wrote:
What is the average of all integers from 1 to 100 that end in 2?

(A) 46

(B) 47

(C) 48

(D) 50

(E) None of these

Figure out only the lowest and highest terms: 2 and 92

In a set of evenly spaced integers, the average is
$$\frac{High + Low}{2}$$

$$\frac{92+2}{2}=\frac{94}{2}=47$$

_________________

Sometimes at night I would sleep open-eyed underneath a sky dripping with stars.
I was alive then.

—Albert Camus

What is the average of all integers from 1 to 100 that end in 2? &nbs [#permalink] 03 Mar 2018, 14:12
Display posts from previous: Sort by