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

Redeem

What is the probability of rolling two fair dice and

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Wed Feb 21, 2018 4:34 am
Vincen wrote:What is the probability of rolling two fair dice and having at least one die show an even number?

A. 35/36
B. 3/4
C. 1/2
D. 1/4
E. 1/36
P(at least 1 even number) = 1 - P(2 odd numbers).

Of the 6 numbers on a die, 1/2 are odd, 1/2 are even.
Thus:
P(2 odd numbers) = 1/2 * 1/2 = 1/4.
P(at least 1 even number) = 1 - 1/4 = 3/4.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top

GMAT/MBA Expert

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

by Scott@TargetTestPrep » Sun Jun 23, 2019 10:20 am
Vincen wrote:What is the probability of rolling two fair dice and having at least one die show an even number?

A. 35/36
B. 3/4
C. 1/2
D. 1/4
E. 1/36
We can use the formula:

P(at least one even) = 1 - P(no evens)

P(no evens) = 3/6 x 3/6 = 1/4.

P(at least one even) = 1 - 1/4 = 3/4.

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Post new topic Post Reply
• Page 1 of 1