coin toss(probability)

[VinD680]

A few weeks ago, I encountered the following question:
If a coin has an equal probability of landing heads up or tails up each time it is flipped , what is the probability that the coin will land heads up exactly twice in 3 consecutive flips ?

I figured this question using the formula
P=nCm*p^m*q^(n-m)
P=3C2*(1/2)^2*(1/2)^1=3/8=0.375

Then I saw another question similar to the one above asking the probability that the coin will land on head twice and tail once out of 3 flips.
I counted the outcomes to be 3/8, but the formula does not seem to work in this case.
So I am wondering what exactly is wrong w/ the formula or is there anything that has to be tweaked to make it work?

Your help is much appreciated!

[RonPurewal]

"2 heads out of 3" and "2 heads, 1 tail" are exactly the same thing, so, any formula should give the same result in both cases.

what was the formula that "didn't work" the second time?

[VinD680]

Never mind. I was plugging it wrong. Anyways, you are the best Ron!
Cheers

[RonPurewal]

ok.
and thanks.