It is currently 19 Sep 2019, 21:18

### 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

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

# A fair coin is tossed 6 times. What is the probability

Author Message
TAGS:
Manager
Joined: 22 Jun 2019
Posts: 133
Followers: 0

Kudos [?]: 14 [0], given: 46

A fair coin is tossed 6 times. What is the probability [#permalink]  06 Sep 2019, 11:59
00:00

Question Stats:

33% (03:12) correct 66% (04:29) wrong based on 3 sessions
A fair coin is tossed 6 times. What is the probability of getting no any two heads on consecutive tosses?

A. $$\frac{21}{64}$$

B. $$\frac{42}{64}$$

C. $$\frac{19}{64}$$

D. $$\frac{19}{42}$$

E. $$\frac{31}{64}$$
[Reveal] Spoiler: OA
Founder
Joined: 18 Apr 2015
Posts: 8139
Followers: 157

Kudos [?]: 1710 [0], given: 7485

Re: A fair coin is tossed 6 times. What is the probability [#permalink]  07 Sep 2019, 09:00
Expert's post
This is a question which is not good or practice. It is too hard for the GRE.
Attachments

solution.jpg [ 23.05 KiB | Viewed 163 times ]

_________________
Intern
Joined: 05 Sep 2019
Posts: 1
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: A fair coin is tossed 6 times. What is the probability [#permalink]  08 Sep 2019, 04:20
Can someone post a mathematical solution to this?
Manager
Joined: 22 Aug 2019
Posts: 61
Followers: 0

Kudos [?]: 32 [1] , given: 8

Re: A fair coin is tossed 6 times. What is the probability [#permalink]  12 Sep 2019, 21:44
1
KUDOS
huda wrote:
A fair coin is tossed 6 times. What is the probability of getting no any two heads on consecutive tosses?

A. $$\frac{21}{64}$$

B. $$\frac{42}{64}$$

C. $$\frac{19}{64}$$

D. $$\frac{19}{42}$$

E. $$\frac{31}{64}$$

TTTTTT (1)

TTTTTH (6)

HTHTTT (4+3+2+1)

HTHTHT (2+2)

= 21 ways

2^6 combinations = 64

21/64

I can't think of a faster way off the top of my head
Re: A fair coin is tossed 6 times. What is the probability   [#permalink] 12 Sep 2019, 21:44
Display posts from previous: Sort by