Consider the following statements:
1.`P(bar(A) uuB) = P(bar(A)) +P(B) - P(bar(A)nnB)`
2.`P(A nn bar(B)) = P(B) - P(A nn B)`
3.`P(A nn B) = P(B) P(A|B)`
Which of the above statements are correts ?

Options

A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1,2 and 3

Answer

B

Explanation

3 sticks can be selected from 5 sticks in `.^(5)c_(3)` ways `.^(5)c_(3)=10`.
Probability that selected sticks from a triangle is
`n(E)=.^(4)c_(3)-1=(4xx3xx2xx1)/(3xx2xx1)-1=4-1=3`
`therefore p(E)=(3)/(10)=0.3`