Question

you flip three coins what is the probability that you get exactly 3 heads , given that you get at least 1 head ?

Answer 1

P(A|B) = P(AB)/P(B)

A = You get exactly 3 heads.
B = You get at least 1 head.

Answer 2

\[\begin{array}{c|cccc}
x & 0 & 1 & 2 & 3 \\\hline
P(X=x) & \frac{1}{8} & \frac{3}{8} & \frac{3}{8} & \frac{1}{8}
\end{array}\]

Answer 3

so its 1/8 ?

Answer 4

no

Answer 5

use mtbender74 formula with the distribution I gave you

Answer 6

noting that AB in this context means A and B.

Answer 7

Also noting that P(B) is P(X=1) + P(X=2) + P(X=3)...

Answer 8

1/7 :)

Answer 9

yes