GMAT Club Olympics 2025 (Day 2): At a tech seminar with a total : Problem Solving (PS)

Last visit was: 21 Apr 2026, 23:41

It is currently 21 Apr 2026, 23:41

Toolkit

Quantitative Questions

Problem Solving (PS)

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

Request Expert Reply

Confirm Cancel

Apr 22
From ‘GMAT Is Not for Me’ to a 695— Beating Her Target by 50 Points
12:30 AM EDT
-
01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 16
Sneak Peek: $200 Off GMAT Prep
12:00 PM EDT
-
11:59 PM EDT
You’re first to know: Save $200 on GMAT prep starting tomorrow, 4/13. Get 6 official practice tests and study with real questions. Be ready to save!
Apr 23
A Non-Native’s Journey to GMAT 695 with V88 (99th percentile)
01:30 AM EDT
-
02:30 AM EDT
Struggling with GMAT Verbal as a non-native speaker? Harsh improved his score from 595 to 695 in just 45 days—and scored a 99 %ile in Verbal (V88)! Learn how smart strategy, clarity, and guided prep helped him gain 100 points.
Apr 23
Free full-length test!
08:00 PM PDT
-
09:00 PM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
Apr 26
Score High on the GMAT with Target Test Prep
10:00 AM EDT
-
11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 27
Try OnDemand GMAT Masterclass
11:00 AM EDT
-
12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 28
Join - GMAT Day!
08:00 AM PDT
-
11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.

GuadalupeAntonia

Yale Moderator

Joined: 04 May 2024

Last visit: 07 Apr 2026

Posts: 59

Own Kudos:

[1]

Given Kudos: 22

Location: Mexico

Schools: Haas '27 Yale '27 Stanford '27 MIT '27 Wharton '27

GMAT Focus 1: 665 Q84 V83 DI80 Verified score

GPA: 3.5

Schools: Haas '27 Yale '27 Stanford '27 MIT '27 Wharton '27

GMAT Focus 1: 665 Q84 V83 DI80 Verified score

Posts: 59

Kudos: 66

[1]

01 Jul 2025, 09:28

Kudos

Bookmarks

ANS C

a= total participants
b= attended a session on cybersecurity
c= attended a session on cloud computing
d= participants attended neither
x= both sessions
a=b+c-x+d
x=b+c+d-a

% of participants that attend both sessions= x/a=(b+c+d-a)/a

Abhiswarup

Joined: 07 Apr 2024

Last visit: 12 Jan 2026

Posts: 198

Own Kudos:

172

[1]

Given Kudos: 42

Location: India

Posts: 198

Kudos: 172

[1]

01 Jul 2025, 09:29

Kudos

Bookmarks

Total Participants = a

Participants attended Cybersecurity session =b

Participants attended Cloud computing = c

Participants attended neither session = d

Using Venn diagram following equation is obtained

a=b+c-b ∩ c+d

let b∩c=x

a=b+c-x+d
solving , x=b+c+d-a

Fraction of participants attended both sessions= (b+c+d-a)/a

Answer is C

shaliny

Joined: 30 Oct 2023

Last visit: 21 Apr 2026

Posts: 120

Own Kudos:

[1]

Given Kudos: 980

Products:

Posts: 120

Kudos: 26

[1]

01 Jul 2025, 09:33

Kudos

Bookmarks

total participants = participants in cybersecurity + participants in cloud computing - participants in both cybersecurity and cloud computing + participants in Neither session
a = b + c - both + d
both = (b + c + d -a)
so fraction = participants in both cybersecurity and cloud computing/ total participants = (b + c + d -a)/a

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

haianh

Joined: 29 Oct 2020

Last visit: 02 Apr 2026

Posts: 45

Own Kudos:

[1]

Given Kudos: 80

Posts: 45

Kudos: 30

[1]

01 Jul 2025, 09:35

Kudos

Bookmarks

Total participants (a) = cybersecurity (b) + cloud (c) - both + neither (d)
both = b+c+d-a
Fraction = $\frac{both}{total} $= $\frac{b+c+d-a}{a}$

Answer: C

FruAdey

Joined: 10 Jul 2024

Last visit: 21 Apr 2026

Posts: 25

Own Kudos:

[1]

Given Kudos: 36

Products:

Posts: 25

Kudos: 16

[1]

01 Jul 2025, 09:42

Kudos

Bookmarks

I did something like this,
let x be people who attend both.
then
people who attend only b : b-x
people who attendes only c : c- x
total to be b-x + c-x + x + d = a
Which means x = (B+ c + d -a )
x/a = (B+ c + d -a )/ a

answer C

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

DyutiB

Joined: 21 Jul 2024

Last visit: 21 Apr 2026

Posts: 25

Own Kudos:

[1]

Given Kudos: 3

Products:

Posts: 25

Kudos: 16

[1]

01 Jul 2025, 09:43

Kudos

Bookmarks

	Cyber	Not Cyber	Total
Cloud Computing	b-a+c+d	a-b-d	c
Not Cloud Computing	a-c-d	d	a-c
Total	b	a-b	a

Ans: b+c+d-a/a (C)

shriwasakshat

Joined: 08 Aug 2024

Last visit: 21 Apr 2026

Posts: 84

Own Kudos:

[1]

Given Kudos: 107

Products:

Posts: 84

Kudos: 62

[1]

01 Jul 2025, 09:49

Kudos

Bookmarks

Total = Group1 + Group2 + Group3 - Both + Neither
Therefore,
a = b + c + - "both" + d
We need to find "both"/a
Then,
"both" = (b + c + d - a)/a,
Hence, option C

JOREDA1234

Joined: 18 Jun 2025

Last visit: 15 Aug 2025

Posts: 12

Own Kudos:

[1]

Posts: 12

Kudos: 11

[1]

01 Jul 2025, 09:50

Kudos

Bookmarks

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

To find the fraction of participants who attended both we need to find: \frac{People who attended both}{Total people}

We already know total number of people is a

Now to find people who attended both sessions we must take the following formula:

=> Total number of participants = People in Cybersecurity + People in Could Computing - People in Both + Attended Neither

Now if we rearrange the equation to find People in Both-

->People in Both = People in Cybersecurity + People in Could Computing - Total number of participants + Attended Neither

Let's substitute values of a, b, c, d in equation:

===> People in Both = b + c - a + d

Final answer: \frac{(People who attended both)}{(Total people)}

= \frac{(b + c - a + d)}{a)}

Answer:
(C)

Manu1995

Joined: 30 Aug 2021

Last visit: 17 Mar 2026

Posts: 81

Own Kudos:

[1]

Given Kudos: 18

Posts: 81

Kudos: 55

[1]

01 Jul 2025, 09:50

Kudos

Bookmarks

Let's say x people attended both sessions.
So:
==>Only cybersecurity = b-x
==>Only cloud computing = c-x
==> Both = x
==> Neither = d
Therefore,
Total = Only cyber + Only cloud + both + Neither
=(b-x) + (c-x) + x + d
= b + c + d - x
But total people also given as a,so:
==> a = b + c + d - x
==> x = b + c + d - a
Now fraction who attended both = x/a
= (b + c + d -a) / a
Correct answer option C

findingmyself

Joined: 06 Apr 2025

Last visit: 14 Mar 2026

Posts: 226

Own Kudos:

165

[1]

Given Kudos: 68

Posts: 226

Kudos: 165

[1]

01 Jul 2025, 09:50

Kudos

Bookmarks

AorB= A+B-AandB+ Neither
a=b+c-both+d (Substituting the values given in the equation)
both=(b+c+d-a)
both/total=(b+c+d-a)/a

Dereno

Joined: 22 May 2020

Last visit: 21 Apr 2026

Posts: 1,398

Own Kudos:

1,373

[1]

Given Kudos: 425

Products:

Posts: 1,398

Kudos: 1,373

[1]

01 Jul 2025, 09:53

Kudos

Bookmarks

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

Let a be the total number of participants.

Let b be the number of Cyber security.

Let c be the number of Cloud Computing.

Let d be the number of participants who has not attended neither session.

Let x be the number of participants who attended both cyber security and cloud computing.

Therefore, a = b-x + x + c-x + d

x = (b+c+d)-a

Fraction that attended both session = x/a

= (b+c+d)-a /a

Option C

VizzyFanboy

Joined: 14 Jul 2023

Last visit: 17 Mar 2026

Posts: 32

Own Kudos:

[1]

Given Kudos: 31

Location: India

Schools: IIMA '26 (A) EPGP '26 (A)

GMAT Focus 1: 675 Q88 V84 DI79 Verified score

Schools: IIMA '26 (A) EPGP '26 (A)

GMAT Focus 1: 675 Q88 V84 DI79 Verified score

Posts: 32

Kudos: 15

[1]

01 Jul 2025, 10:01

Kudos

Bookmarks

Let x be the number of persons who attended both sessions.

Therefore, Total people who took part in the conference = People who only attended Cybersecurity session + People who only attended Cloud Computing session +People who attended both sessions + People who attended neither sessions,
or, a = (b-x)+(c-x)+x+d => x = (b+c+d-a)/a.

Answer = C

Minionion

Joined: 23 Jun 2025

Last visit: 05 Jan 2026

Posts: 31

Own Kudos:

[1]

Given Kudos: 10

Location: Korea, Republic of

Schools: INSEAD Aug '26 (A)

Posts: 31

Kudos: 15

[1]

01 Jul 2025, 10:03

Kudos

Bookmarks

Let x= attended both sessions.

then total a= b+c+d -x
x= b+c+d-a

Thus, x/total = b+c+d-a / a => answer is C

embellor

Joined: 26 Feb 2025

Last visit: 21 Dec 2025

Posts: 24

Own Kudos:

[1]

Location: Nigeria

Posts: 24

Kudos: 3

[1]

01 Jul 2025, 10:06

Kudos

Bookmarks

Total Paricipant = a
Cyber Security = b
Cloud Computing = c
Non = d
Let both Cyber Security and Cloud Computing be, e

So a = b-e + c-e + d + e

e = (b + c +d -a)/a

The correct answer is C

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

DataGuyX

Joined: 23 Apr 2023

Last visit: 02 Apr 2026

Posts: 111

Own Kudos:

[1]

Given Kudos: 161

Location: Brazil

Concentration: Entrepreneurship, Technology

Schools: Booth '26 (A$) Kellogg '26 (A) Sloan '26 (D) Stanford '26 (D) Haas '26 (D) HBS '26 (D)

GMAT Focus 1: 675 Q79 V85 DI86 Verified score

GPA: 7.3

Schools: Booth '26 (A$) Kellogg '26 (A) Sloan '26 (D) Stanford '26 (D) Haas '26 (D) HBS '26 (D)

GMAT Focus 1: 675 Q79 V85 DI86 Verified score

Posts: 111

Kudos: 77

[1]

01 Jul 2025, 10:14

Kudos

Bookmarks

Total = A + B + Neither - AUB

a = b + c + d - Both
Both = b + c + d - a

Fraction = Both / a = (b + c + d - a)/a

UfuomaOh

McCombs School Moderator

Joined: 14 Sep 2023

Last visit: 07 Mar 2026

Posts: 83

Own Kudos:

[1]

Given Kudos: 14

Posts: 83

Kudos: 50

[1]

01 Jul 2025, 10:18

Kudos

Bookmarks

At a tech seminar with a total participants, b attended a session on cybersecurity, and c attended a session on cloud computing. If exactly d participants attended neither session, then in terms of a, b, c, and d, what fraction of the participants attended both sessions?

a= total participants
b=cybersecurity attendees
c=cloud computing attendees
d=neither

No of participants who attended at least one session= a-d

Again, number of participants who attended at least one session is
= b +c - x

where x is participants who attended both sessions

b + c- x=a-d

x= b + c - a + d

Hence, the fraction of the participants attended both sessions is

(B+C-A+D)/A

Decimal

Joined: 20 Jul 2022

Last visit: 03 Oct 2025

Posts: 9

Own Kudos:

[1]

Given Kudos: 16

Posts: 9

Kudos: 9

[1]

01 Jul 2025, 10:22

Kudos

Bookmarks

What is Given :
Total Participants = a
Attendees for Cybersecurity = b
Attendees for Cloud computing = c
Participants attended no sessions = d

What is Asked?

'Fraction of participants attended both sessions' => [attendees common for both Cybersecurity and Cloud computing sessions][/Total Attendees]

Solution :

Attendees common for both Cybersecurity and Cloud computing sessions, implies

Total attendance in Cybersecurity and Cloud computing session (a) - Total Participants who attended any session (b) ; as there is an overlap of participants in Cybersecurity and Cloud computing sessions
=> (a) = b+c ;
(b) = Total participants - Participants attended no session = a-d
=> Attendees common for both Cybersecurity and Cloud computing sessions = (b+c) - (a-d) = b+c-a+d

Now, we know total number of attendees = a

Therefore, the Fraction of participants who attended both sessions = [b+c+d-a][/a]
Option C is the answer.

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

SRIVISHUDDHA22

Joined: 08 Jan 2025

Last visit: 21 Apr 2026

Posts: 94

Own Kudos:

[1]

Given Kudos: 332

Location: India

Schools: ISB '26

GPA: 9

Products:

Schools: ISB '26

Posts: 94

Kudos: 60

[1]

01 Jul 2025, 10:25

Kudos

Bookmarks

Bunuel

This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

Show Spoiler

Attachment:

GMAT-Club-Forum-bsr08jca.png [ 344.17 KiB | Viewed 256 times ]

AD21

Joined: 12 Jan 2024

Last visit: 23 Dec 2025

Posts: 38

Own Kudos:

[1]

Given Kudos: 31

Location: United States

Posts: 38

Kudos: 23

[1]

01 Jul 2025, 10:26

Kudos

Bookmarks

Option C

total no of participants :a
No in cybersecurity:b
No. in cloud computing :c
Neither-d
No of no Cloud Computing: (a-c)
No. of no Cloud Computing but yes to Cybersecurity: (a-c-d)
Hence no of both cybersecurity and cloud computing: (c-a+b+d)
Fraction of participants attending both sessions= (c-a+b+d)/a

iCheetaah

Joined: 13 Nov 2021

Last visit: 21 Apr 2026

Posts: 81

Own Kudos:

[1]

Given Kudos: 1

Location: India

Products:

Posts: 81

Kudos: 72

[1]

01 Jul 2025, 10:27

Kudos

Bookmarks

So, this is what we are given:

Total # of participats = a
# of attendees for cybersecurity = b
# of attendees for cloud computing = c
# of participants that attended neither cybersecurity or cloud computing = d

We have to find = $\frac{Participants that attended both cybersecurity and cloud computing}{Total # of participants } $

For two sets, we know that

Total = A + B - both + neither

Putting in the values we have from the info given:

a = b + c - both + d

Solving for "both", we get,

both = b+c+d-a

Dividing this by the total # of participants, we get:

$\frac{ b+c+d-a }{a}$

And that is the correct answer, option C