Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 299

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

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,891

5/32 is correct.

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.

Offline

**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 299

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 !

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,797

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

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 299

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,964

Hi Al-Allo;

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

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 299

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

Offline

Pages: **1**