Math Is Fun Forum

Al-Allo

Member

Registered: 2012-08-23

Posts: 324

probability

I have just a little question about this : If I toss a coin 5 times, what is the probability of getting 4 tails and 1 head ? I think the answer is 5/32 ? Is this any good ? THanks

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: probability

5/32 is correct.

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Al-Allo

Member

Registered: 2012-08-23

Posts: 324

Re: probability

Omg im happy to know that because in my book it says its 4/32 ?!? And here is another one, what is the prob that it will land 3 times on head and 2 times on tails ? I got 9/32 but in my book it says 8/32 ?!? There is always 1 of difference, we could say it's an error ? Thanks !

Bob

Administrator

Registered: 2010-06-20

Posts: 10,140

Re: probability

hi Al-Allo

Welcome to the forum.

Stay on-line.  I'm just working it out.

1 5 10 10 5 1

It should be 10/32

hhhtt, hhtht, hhtth, hthht, hthth, htthh, thhht, thhth, ththh, tthhh

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Al-Allo

Member

Registered: 2012-08-23

Posts: 324

Re: probability

oh yes you're right. i noticed i missed one, so thanks ! finaly, my book wasnt right ! thanks you two !

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: probability

Hi Al-Allo;

Both of those are binomial distribution problems. What is the name of the book?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Al-Allo

Member

Registered: 2012-08-23

Posts: 324

Re: probability

It's not written in English ... ^^ Even, it's only exercises, nothing more lol