Probability

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

Redeem

This topic has expert replies

Post new topic Post Reply

Previous Topic Next Topic

swerve: Legendary Member; Posts: 2499; Joined: Sun Oct 29, 2017 2:04 pm; Followed by:6 members

Probability

by swerve » Wed Apr 15, 2020 3:05 pm

Timer

00:00

Your Answer

Global Stats

At a certain amateur bands rock show the ratio of freaks to nerds to geeks is 1:2:3. If these are the only types of people in the crowd, and each person in the crowd has the same chance of yelling "rock on!", what are the chances that the next person who yells "rock on!" will be a geek?

A. 1/6
B. 1/3
C. 1/2
D. 2/3
E. 5/6

The OA is C

Source: Economist GMAT

Quote

Source: Beat The GMAT — Problem Solving | Wed Apr 15, 2020 3:05 pm

GMAT/MBA Expert

Jay@ManhattanReview: GMAT Instructor; Posts: 3008; Joined: Mon Aug 22, 2016 6:19 am; Location: Grand Central / New York; Thanked: 470 times; Followed by:34 members

Re: Probability

by Jay@ManhattanReview » Thu Apr 16, 2020 12:38 am

swerve wrote: ↑
Wed Apr 15, 2020 3:05 pm
At a certain amateur bands rock show the ratio of freaks to nerds to geeks is 1 : 2 : 3. If these are the only types of people in the crowd, and each person in the crowd has the same chance of yelling "rock on!", what are the chances that the next person who yells "rock on!" will be a geek?

A. 1/6
B. 1/3
C. 1/2
D. 2/3
E. 5/6

The OA is C

Source: Economist GMAT

Given that the ratio of freaks to nerds to geeks is 1 : 2 : 3, say the no. of freaks = x, no. of nerds = 2x, and no. of geeks = 3x; thus, the total no. of people in the crowd = 6x

=> the chances that the next person who yells "rock on!" will be a geek = 3x/6x = 1/2

The correct answer: C

Hope this helps!

-Jay
_________________
Manhattan Review Test Prep

Locations: Manhattan Review Bangalore | Chennai | GRE Prep Hyderabad | Himayatnagar GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

Quote

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8086; Joined: Sat Apr 25, 2015 10:56 am; Location: Los Angeles, CA; Thanked: 43 times; Followed by:29 members

Re: Probability

by Scott@TargetTestPrep » Mon Apr 27, 2020 3:19 am

swerve wrote: ↑
Wed Apr 15, 2020 3:05 pm
At a certain amateur bands rock show the ratio of freaks to nerds to geeks is 1:2:3. If these are the only types of people in the crowd, and each person in the crowd has the same chance of yelling "rock on!", what are the chances that the next person who yells "rock on!" will be a geek?

A. 1/6
B. 1/3
C. 1/2
D. 2/3
E. 5/6

The OA is C

Source: Economist GMAT