# Excel - IF Function Problem - Expert Solution

Question description:
This user has given permission to use the problem statement for this blog.

Help! In a coin toss I have a 1 in 2 (fifty-fifty) chance of getting heads or tails. I need a formula to determine my chance of getting 4 heads in a row or 4 tails in a row out of 10 coin tosses. If I get 4 in a row I win. What formula can I use to determine my chances of winning if I repeat the 10 tosses for hundreds or thousands of times? I get as far as =RANDBETWEEN(0,1) but I have not been able to figure out what formula to use to determine if there are 4 in a row in a group of 10 tosses, times thousands of groups with 10 tosses in each group. Thank-you for any help you can provide.
Solved by V. F. in 51 mins
This is the chat thread from the real Excelchat help session. It contains no private user information.
User 18/03/2018 - 07:07
p.s., how can i save a copy of our chat and worksheet so I can study/understand it after our session ends?
Excelchat Expert 18/03/2018 - 07:07
Hi Welcome to Gotit
Excelchat Expert 18/03/2018 - 07:08
Its a probability question
Excelchat Expert 18/03/2018 - 07:09
10C2/2^10
Excelchat Expert 18/03/2018 - 07:09
is the propability
Excelchat Expert 18/03/2018 - 07:09
10C4
Excelchat Expert 18/03/2018 - 07:09
/2^10
User 18/03/2018 - 07:11
ok, I understand that it is probability,
Excelchat Expert 18/03/2018 - 07:12
use 10C4/2^10
Excelchat Expert 18/03/2018 - 07:13
(10*9*8*7/4*3*2*1)/2^10
User 18/03/2018 - 07:17
Probability of 4 heads or four tailess in a row with 10 tosses, repeated multiple times, each group of 10 distinct from the next group of 10.
Excelchat Expert 18/03/2018 - 07:19
hello
Excelchat Expert 18/03/2018 - 07:19
its a probability question
Excelchat Expert 18/03/2018 - 07:19
not excel related
User 18/03/2018 - 07:20
hello, i'm still here. but how can i formulate it in excel?
Excelchat Expert 18/03/2018 - 07:21
you can't find it but you can simulate
User 18/03/2018 - 07:22
that is my question, what formula can i use to simulate it in excel
Excelchat Expert 18/03/2018 - 07:26
four heads in a row we can find using excel
Excelchat Expert 18/03/2018 - 07:27
we can find n heads tossed in 10 tosses
User 18/03/2018 - 07:28
yes, using =RANDBETWEEN(0,1)
User 18/03/2018 - 07:30
Here is the actual wording of the problem I'm trying to figure out how to simulate.
User 18/03/2018 - 07:30
You are going to play a game where you bet a dollar and get to flip a coin ten (10) times. If you get four (4) heads in a row, you win. If you make the tenth flip without getting four heads in a row, you lose. Run this game ten thousand times (10,000). Approximately what is the probability that you will win?
Excelchat Expert 18/03/2018 - 07:34
User 18/03/2018 - 07:35
pardon me? I don't see it.
Excelchat Expert 18/03/2018 - 07:36
Excelchat Expert 18/03/2018 - 07:36
D3,D4
Excelchat Expert 18/03/2018 - 07:36
E3,E4,F4,F5
User 18/03/2018 - 07:38
thank you. that was not showing on my screen, I had to scroll over to see it, How can I save this so i have time to study and copy it b4 we time out?
Excelchat Expert 18/03/2018 - 07:38
yes
User 18/03/2018 - 07:39
how?
Excelchat Expert 18/03/2018 - 07:39
Excelchat Expert 18/03/2018 - 07:40
User 18/03/2018 - 07:41
Excelchat Expert 18/03/2018 - 07:41
Where s the preview sheet?
Excelchat Expert 18/03/2018 - 07:42
have you done anything?
Excelchat Expert 18/03/2018 - 07:42
I can't see sheet in document preview window
Excelchat Expert 18/03/2018 - 07:44
Hello
User 18/03/2018 - 07:45
i have the Document Preview sheet on the screen, but i do not see any command to download it.
Excelchat Expert 18/03/2018 - 07:45
I am unable to preview document window
Excelchat Expert 18/03/2018 - 07:46
I think I have to write formula again
User 18/03/2018 - 07:48
I can see the preview sheet, and when I click on the cells I see the formula, but I am unable to find anything that allows me to download it
Excelchat Expert 18/03/2018 - 07:49
Copy the data to your sheet CTRL C and CTRL V
User 18/03/2018 - 07:51
Excelchat Expert 18/03/2018 - 07:52
I will send you the sheet
Excelchat Expert 18/03/2018 - 07:52
it
Excelchat Expert 18/03/2018 - 07:52
wait
User 18/03/2018 - 07:53
Excelchat Expert 18/03/2018 - 07:55
oK
Excelchat Expert 18/03/2018 - 07:55
User 18/03/2018 - 07:55
ok. goodbye

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