GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 14 Oct 2019, 06:33

### 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

# Robert tossed a fair coin 3 times. What is the probability that the co

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58311
Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

27 Dec 2015, 09:04
00:00

Difficulty:

15% (low)

Question Stats:

75% (01:05) correct 25% (01:18) wrong based on 174 sessions

### HideShow timer Statistics

Robert tossed a fair coin 3 times. What is the probability that the coin landed heads up exactly twice?

A. 0.125
B. 0.250
C. 0.375
D. 0.750
E. 0.875

_________________
Director
Joined: 20 Feb 2015
Posts: 767
Concentration: Strategy, General Management
Re: Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

30 Dec 2015, 04:51
Total outcomes = HHH HHT HTT HTH TTT TTH THT THH
required = HHT HTH THH
probability =3/8=0.375
Marshall & McDonough Moderator
Joined: 13 Apr 2015
Posts: 1686
Location: India
Re: Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

30 Dec 2015, 04:57
Total number of outcomes = 2 * 2 * 2 = 8
Out of 3 times we need heads exactly 2 times = 3C2 = 3

Probability = 3/8 = 0.375
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 8001
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

30 Dec 2015, 05:49
Forget conventional ways of solving math questions. In PS, IVY approach is the easiest and quickest way to find the answer.

Robert tossed a fair coin 3 times. What is the probability that the coin landed heads up exactly twice?

A. 0.125
B. 0.250
C. 0.375
D. 0.750
E. 0.875

The probability is exactly same as the cion landed tail up once. That is 3*(1/2)^3 = 3/8 =0.375.

The answer is, therefore, (C).
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Senior Manager
Joined: 24 Nov 2015
Posts: 491
Location: United States (LA)
Re: Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

02 Apr 2016, 05:49
possible outcomes after tossing a fair coin 3 times:
HHH
HHT
HTH
HTT
THH
THT
TTH
TTT

out of that only 3 favourable cases are required
probability = 3/8 = 0.375
Answer - C
Non-Human User
Joined: 09 Sep 2013
Posts: 13110
Re: Robert tossed a fair coin 3 times. What is the probability that the co  [#permalink]

### Show Tags

24 Mar 2018, 10:54
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: Robert tossed a fair coin 3 times. What is the probability that the co   [#permalink] 24 Mar 2018, 10:54
Display posts from previous: Sort by

# Robert tossed a fair coin 3 times. What is the probability that the co

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne