## If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what

##### This topic has expert replies
Moderator
Posts: 7114
Joined: Thu Sep 07, 2017 4:43 pm
Followed by:23 members

### If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what

by BTGmoderatorDC » Sat Jun 18, 2022 10:58 pm

00:00

A

B

C

D

E

## Global Stats

If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?

A. 3/5
B. 1/2
C. 1/5
D. 1/8
E. 1/32

OA E

Source: GMAT Prep

Master | Next Rank: 500 Posts
Posts: 416
Joined: Thu Oct 15, 2009 11:52 am
Thanked: 27 times

### Re: If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times,

by regor60 » Mon Jun 27, 2022 10:09 am
The question is asking for the probability of a set of outcomes which occur in a specific order.

Since each toss is independent of the other and each face has a 1/2 chance of appearing the probability is [spoiler]1/32, E[/spoiler]

If the question had asked for probability of 3 heads and 2 tails occurring in 5 tosses, then would need to consider all orders that produce the result

### GMAT/MBA Expert

GMAT Instructor
Posts: 16185
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

### Re: If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times,

by [email protected] » Mon Jun 27, 2022 10:37 am
BTGmoderatorDC wrote:
Sat Jun 18, 2022 10:58 pm
If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?

A. 3/5
B. 1/2
C. 1/5
D. 1/8
E. 1/32

OA E

Source: GMAT Prep
We want P(heads on 1st AND heads on 2nd AND heads on 3rd AND tails on 4th AND tails on 5th)
= P(heads on 1st) x P(heads on 2nd) x P(heads on 3rd) x P(tails on 4th) x P(tails on 5th)
= 1/2 x 1/2 x 1/2 x 1/2 x 1/2
= 1/32

Brent Hanneson - Creator of GMATPrepNow.com

### GMAT/MBA Expert

GMAT Instructor
Posts: 6810
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

### Re: If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times,

by [email protected] » Fri Jan 27, 2023 8:24 am
BTGmoderatorDC wrote:
Sat Jun 18, 2022 10:58 pm
If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?

A. 3/5
B. 1/2
C. 1/5
D. 1/8
E. 1/32

OA E

Source: GMAT Prep
The probability that the first 3 flips are heads and last 2 flips are tails is:

P(HHHTT) = (1/2)^5 = 1/32.
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "url": "https://www.beatthegmat.com/if-a-certain-coin-is-flipped-the-probability-that-the-coin-will-land-heads-is-1-2-if-the-coin-is-flipped-5-times-what-t330550.html", "fetch_time": 1680140695000000000, "content_mime_type": "text/html", "warc_filename": "crawl-data/CC-MAIN-2023-14/segments/1679296949093.14/warc/CC-MAIN-20230330004340-20230330034340-00786.warc.gz", "warc_record_offset": 741862046, "warc_record_length": 12382, "token_count": 1048, "char_count": 3067, "score": 3.890625, "int_score": 4, "crawl": "CC-MAIN-2023-14", "snapshot_type": "latest", "language": "en", "language_score": 0.8995780348777771, "file_path": "/sailhome/yjruan/project/latent-lm/data/processed/finemath-4plus/finemath-4plus/train-00041-of-00064.parquet"}