Help me. I will reward you

Question

anonymous · Answer

?

anonymous · Answer

What is your question?

anonymous · Answer

Is this correct?

anonymous · Answer

Okay, so first of all, there are 5 marbles total, right?

anonymous · Answer

Right.

anonymous · Answer

For part 1, what's the probability to draw a red marble the first time? What's the probability to draw a red the second time?

anonymous · Answer

Are you uncertain about any of the answers?

anonymous · Answer

The formula is p(Red and Red) = (2/5) • (2/5) 
Correct?

anonymous · Answer

Yes, I am for the ones that say "Without replacement".

anonymous · Answer

Yeah, you have it right. I made a mistake. :)

anonymous · Answer

Lol.

anonymous · Answer

Okay, when it is without replacement, then you just redo it after having removed the marble.

anonymous · Answer

Is there a formula for it?

anonymous · Answer

white and white  becomes  2/5   and  1/4,   while white and red becomes  2/5  and 2/4

anonymous · Answer

Alright.

anonymous · Answer

Does it make sense how I got that?

anonymous · Answer

Ohh!! Alright. I see. (:

anonymous · Answer

the 2 became 1 because a white marble was removed

anonymous · Answer

Ohh.

anonymous · Answer

The best way to visualize it:$$
\begin{array}{c|c}
\text{ blue } & 1 \
\text{ white } & 2 \
\text{ red } & 2\
\hline
\text{ total } & 5\
\end{array}
$$We remove a white marble and it becomes:$$
\begin{array}{c|c}
\text{ blue } & 1 \
\text{ white } & 1 \
\text{ red } & 2\
\hline
\text{ total } & 4\
\end{array}
$$