Thread: [SOLVED] coin tosses

question:

We toss a coin 5 times in a row. Find the probability that the number of tales is at least 1.

I believe the answer is 4/5 can someone confirm or deny this please.

Originally Posted by graffitihead

We toss a coin 5 times in a row. Find the probability that the number of tales is at least 1.
I believe the answer is 4/5 can someone confirm or deny this please.

Well it is actually $\displaystyle \frac{6}{32}$. Can you see why?

There are $\displaystyle 2^5=32$ possible outcomes here. Why?
So where does the 6 come from?

I understand the 32 but it seems like it would be 5 choose 1 over 32 or 5/32.

would you explain the 6 please.

Originally Posted by graffitihead

I understand the 32 but it seems like it would be 5 choose 1 over 32 or 5/32. would you explain the 6 please.

Sorry, I misread your question. I read it as "at most one”.
So the answer to at one is $\displaystyle \frac{31}{32}$.
The only case we cannot allow is HHHHH.