# Thread: Help with Sample Space

1. ## Help with Sample Space

A coin is flipped 4 times. Let A be the event that we record an equal number of HEADS and TAILS.
A) Write down the event A by explicitly writing its elements between curly braces.
B) Evaluate P(A)

2. ## Re: Help with Sample Space

Originally Posted by BlueandGold
A coin is flipped 4 times. Let A be the event that we record an equal number of HEADS and TAILS.
A) Write down the event A by explicitly writing its elements between curly braces.
B) Evaluate P(A)
$\begin{array}{*{20}{c}} H&H&H&H \\ H&H&H&T \\ H&H&T&H \\ H&H&T&T \\ H&T&H&H \\ H&T&H&T \\ H&T&T&H \\ H&T&T&T \\ T&H&H&H \\ T&H&H&T \\ T&H&T&H \\ T&H&T&T \\ T&T&H&H \\ T&T&H&T \\ T&T&T&H \\ T&T&T&T \end{array}$

Now you tell us the answers.

3. ## Re: Help with Sample Space

Originally Posted by Plato
$\begin{array}{*{20}{c}} H&H&H&H \\ H&H&H&T \\ H&H&T&H \\ H&H&T&T \\ H&T&H&H \\ H&T&H&T \\ H&T&T&H \\ H&T&T&T \\ T&H&H&H \\ T&H&H&T \\ T&H&T&H \\ T&H&T&T \\ T&T&H&H \\ T&T&H&T \\ T&T&T&H \\ T&T&T&T \end{array}$

Now you tell us the answers.

I got A: {HHTT, HTHT, HTTH, THHT, THTH, TTHH}
B: 6/16 = 3/8

4. ## Re: Help with Sample Space

Originally Posted by BlueandGold
I got A: {HHTT, HTHT, HTTH, THHT, THTH, TTHH}
B: 6/16 = 3/8
That is correct. Did you learn anything from that? If so, then what?

5. ## Re: Help with Sample Space

Originally Posted by Plato
That is correct. Did you learn anything from that? If so, then what?
I learned that I'm over-thinking these problems.