Question

You toss 3 coins. What is the probability that you get exactly 2 heads given that you got at least one head

Answer 1

ok i got 1/4 for this

Answer 2

3/7

Answer 3

because its 1/2*1/2 right?

Answer 4

Since this is a small number ouf outcomes, you can kind of fake it...

There are 2 outcomes to a cointoss and 3 coins... 2^3 possible outcomes. (8) and one of them is all heads and one of them is all tails. only one way to make either of those. everything else is 1 head or 2 heads. There are 3 ways to make 1 head and 3 ways to make 1 tail (2 heads..)

So you have 7 outcomes with at least one head. and only 3 ways to make 2 heads (1st, 2nd or 3rd is a tail) so him1618 is correct. 3.7

Answer 5

Sorry, that should read 3/7....

Answer 6

i have a feeling its 3/7

Answer 7

Isn't it 3/4 for the first head (hhh,ttt,tth,thh) and 1/3 for the second (hh,tt,th) so 1/4?