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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Peter rolls two dice at the same time. What is the probability that he will roll a double?

a) 1/12

b) 1/36

c) 1/6

d) 5/12

e) 1/3

Notice that the probability doesn't change if we roll one die first and the other die second. So, let's do this.

Let die #1 the first die, and let die #2 be the second dice

P(both dice are the same) = P(die #1 is any value AND die #2 matches die #1) = P(die #1 is any value) x P(die #2 matches die #1) = 1 x 1/6 = 1/6 = C

ASIDE: Some people might wonder how I found the first probability to equal 1. We need to recognize that the first die can be any value and, in order to get a double, the second guy must match the first die. Once we have rolled the first die, there is a probability of 1/6 that the second die matches the first die.

RELATED VIDEO

_________________

Brent Hanneson – Founder of gmatprepnow.com

gmatclubot

Re: Peter rolls two dice at the same time. What is the probabili
[#permalink]
15 Nov 2017, 13:11