Last visit was: 26 Apr 2026, 22:43 It is currently 26 Apr 2026, 22:43
Home
Messages
Tests
Schools
Events
Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 26 Apr 2026
Posts: 109,921
Own Kudos:
811,470
 [1]
Given Kudos: 105,908
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,921
Kudos: 811,470
 [1]
From the integers from 2 to 40 inclusive, one integer is selected at 23 Feb 2021, 09:30
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

25% (medium)

Question Stats:

73% (01:33) correct 27% (01:58) wrong based on 90 sessions

History

Date
Time
Result
Not Attempted Yet
From the integers from 2 to 40 inclusive, one integer is selected at random. What is the probability that it is a perfect square or a multiple of 9 ?


A. 17/39

B. 4/13

C. 3/13

D. 7/39

E. 4/39
ShowHide Answer
Official Answer
D
Most Helpful Reply
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,471
 [5]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,471
 [5]
From the integers from 2 to 40 inclusive, one integer is selected at 23 Feb 2021, 11:50
3
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Bunuel
From the integers from 2 to 40 inclusive, one integer is selected at random. What is the probability that it is a perfect square or a multiple of 9 ?

A. 17/39
B. 4/13
C. 3/13
D. 5/39
E. 4/39
Show more

P(selected integer is a perfect square or a multiple of 9) = (number of integers that are perfect squares or multiples of 9)/(total number of integers from 2 to 40 inclusive)

Number of integers from x to y inclusive equals y - x + 1
So, the number of integers from 2 to 40 inclusive = 40 - 2 + 1 = 39

At this point it's probably easiest to just list all integers that are perfect squares or multiples of 9.
Perfect squares: 4, 9, 16, 25, 36 (5 integers)
Multiples of 9: 9, 18, 27, 36 (2 integers, since we don't want to count 9 and 36 twice)
So, there are 7 integers that are perfect squares or multiples of 9:

P(selected integer is a perfect square or a multiple of 9) = 7/39

Answer:????
General Discussion
User avatar
Jawad001
User avatar
Joined: 14 Sep 2019
Last visit: 10 Nov 2022
Posts: 216
Own Kudos:
153
Given Kudos: 31
Posts: 216
Kudos: 153
From the integers from 2 to 40 inclusive, one integer is selected at 24 Feb 2021, 04:27
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel wrote:
From the integers from 2 to 40 inclusive, one integer is selected at random. What is the probability that it is a perfect square or a multiple of 9 ?

A. 17/39
B. 4/13
C. 3/13
D. 5/39
E. 4/39

Solution:

Number of Integers from 2 to 40 = 40 - 2 + 1 = 39

Number of perfect square from 2 to 40, inclusive = 4,9,16,25,36
Number of multiple of from 2 to 40, inclusive = 9,18,27,36

Desired probability = 5/ 39 + 4/ 39
= 9/39 = 3/13

Answer: C
User avatar
Pigna351
User avatar
Joined: 23 Sep 2024
Last visit: 09 Mar 2025
Posts: 2
Given Kudos: 11
Posts: 2
Kudos: 0
From the integers from 2 to 40 inclusive, one integer is selected at 14 Nov 2024, 07:38
Kudos
Add Kudos
Bookmarks
Bookmark this Post
BrentGMATPrepNow
Bunuel
From the integers from 2 to 40 inclusive, one integer is selected at random. What is the probability that it is a perfect square or a multiple of 9 ?

A. 17/39
B. 4/13
C. 3/13
D. 5/39
E. 4/39

P(selected integer is a perfect square or a multiple of 9) = (number of integers that are perfect squares or multiples of 9)/(total number of integers from 2 to 40 inclusive)

Number of integers from x to y inclusive equals y - x + 1
So, the number of integers from 2 to 40 inclusive = 40 - 2 + 1 = 39

At this point it's probably easiest to just list all integers that are perfect squares or multiples of 9.
Perfect squares: 4, 9, 16, 25, 36 (5 integers)
Multiples of 9: 9, 18, 27, 36 (2 integers, since we don't want to count 9 and 36 twice)
So, there are 7 integers that are perfect squares or multiples of 9:

P(selected integer is a perfect square or a multiple of 9) = 7/39

Answer:????
Show more
Sorry for the question, but if it is asked the probability of a number which is a perfect square OR a multiple of 9 then the numbers 9 and 36 belong to both categories so they are not perfect square OR multiples of nine. Wouldn't better to consider only 4,16,25,18 and 27? Hence the answer will be 5/39.
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 26 Apr 2026
Posts: 109,921
Own Kudos:
811,470
 [1]
Given Kudos: 105,908
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,921
Kudos: 811,470
 [1]
From the integers from 2 to 40 inclusive, one integer is selected at 14 Nov 2024, 08:16
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Pigna351
BrentGMATPrepNow
Bunuel
From the integers from 2 to 40 inclusive, one integer is selected at random. What is the probability that it is a perfect square or a multiple of 9 ?

A. 17/39
B. 4/13
C. 3/13
D. 5/39
E. 4/39

P(selected integer is a perfect square or a multiple of 9) = (number of integers that are perfect squares or multiples of 9)/(total number of integers from 2 to 40 inclusive)

Number of integers from x to y inclusive equals y - x + 1
So, the number of integers from 2 to 40 inclusive = 40 - 2 + 1 = 39

At this point it's probably easiest to just list all integers that are perfect squares or multiples of 9.
Perfect squares: 4, 9, 16, 25, 36 (5 integers)
Multiples of 9: 9, 18, 27, 36 (2 integers, since we don't want to count 9 and 36 twice)
So, there are 7 integers that are perfect squares or multiples of 9:

P(selected integer is a perfect square or a multiple of 9) = 7/39

Answer:????
Sorry for the question, but if it is asked the probability of a number which is a perfect square OR a multiple of 9 then the numbers 9 and 36 belong to both categories so they are not perfect square OR multiples of nine. Wouldn't better to consider only 4,16,25,18 and 27? Hence the answer will be 5/39.
Show more

No need to apologize! Actually, "or" in probability means either condition can be true, and it does include cases where both conditions overlap.

So, when asked for the probability that a number is a perfect square or a multiple of 9, we need to count all integers that meet either condition. Numbers like 9 and 36, which meet both conditions, are still counted but only once to avoid double-counting. Therefore, the correct answer includes 4, 9, 16, 25, 36, 18, and 27, giving 7 numbers in total.

So the probability is 7/39.
Moderators:
Bunuel
Math Expert
109921 posts
Krunaal
Tuck School Moderator
852 posts