# dice questions

• Dec 4th 2006, 03:42 PM
papa_chango123
dice questions
I have these two questions and just want to make sure they are right:

5.6 Determine the probability of the following:

a. If three dice are rolled, that all will be odd = 1/2

b. If two coins are flipped, that they both will land the same = 1/2

Can someone please tell me if this is correct. Thanks.
• Dec 4th 2006, 03:50 PM
Quick
Quote:

Originally Posted by papa_chango123
I have these two questions and just want to make sure they are right:

5.6 Determine the probability of the following:

a. If three dice are rolled, that all will be odd = 1/2

b. If two coins are flipped, that they both will land the same = 1/2

Can someone please tell me if this is correct. Thanks.

You are incorrect in both.

a. If three dice are rolled, that all will be odd

There is 1/2 chance that one die will land odd.

So for three dice its: $\displaystyle \frac{1}{2}\times\frac{1}{2}\times\frac{1}{2}=\fra c{1}{8}$

So it's only a 1/8 chance :eek:

Now you try the coins
• Dec 4th 2006, 04:01 PM
papa_chango123
Ok I understand how you got the dice but on the coins here is my logic:

The coins flipped could be 4 probable:

HH, HT, TT, TH

So they could both land the same 2 times out of 4. Would that not be

2/4 = 1/2?
• Dec 4th 2006, 04:08 PM
Quick
Quote:

Originally Posted by papa_chango123
Ok I understand how you got the dice but on the coins here is my logic:

The coins flipped could be 4 probable:

HH, HT, TT, TH

So they could both land the same 2 times out of 4. Would that not be

2/4 = 1/2?

Yes it would be :o (I tend to misread questions)

Just for you to think of it mathwise:

Whatever the first coin lands on will work, but the other coin has only 1/2 chance of landing the same way.

In math thats: $\displaystyle 1\times\frac{1}{2}=\frac{1}{2}$
• Dec 4th 2006, 04:15 PM
papa_chango123
Thanks for the help