Question

If P(A)=3
P(B)
=
NIL
and P(AUB) = what is P(An B)?
5'
A. 2
15
B.
3
15
c.
15
D.
11
15

Answer 1

We know that,

$P(A\cup B)=P(A)+P(B)-P(A\cap B)$

which means

$P(A\cap B)=P(A)+P(B)-P(A\cup B)$

Now insert the data to get,

$P(A\cap B)=\frac{1}{3}+\frac{2}{5}-\frac{3}{5}=\frac{1}{3}-\frac{1}{5}=\frac{5-3}{3\cdot5}=\boxed{\frac{2}{15}}$

Hope this helps :)