Question

Class 12 probability question​

Answer 1

Answer:

here is your answer guy✌

Answer 2

$\large\underline{\sf{Solution-}}$

$\rm\:P(not \: A) = 0.7$

So,

$\rm\:P(A) = 1 - P(not \: A) =1 - 0.7 = 0.3$

Now,

It is given that

$\rm \: P(B) = 0.7$

Also,

$\rm \: P\bigg(\dfrac{B}{A} \bigg) = 0.5$

So,

$\rm \: \dfrac{P(B \: \cap \: A)}{P(A)} = 0.5$

$\rm \: \dfrac{P(B \: \cap \: A)}{0.3} = 0.5$

$\rm \: P(B \: \cap \: A)= 0.5 \times 0.3$

$\rm \: P(B \: \cap \: A)= 0.15$

So,

$\rm \: P\bigg(\dfrac{A'}{B'} \bigg)$

$\rm \: = \: \: \dfrac{P(B' \cap \: A')}{P(B')}$

$\rm \: = \: \: \dfrac{1 - P(B\cup \: A)}{P(A')}$

$\rm \: = \: \: \dfrac{1 - P(A) - P(B) + P(A \cap \: B)}{1 - P(B)}$

$\rm \: = \: \: \dfrac{1 - 0.3 - 0.7 + 0.15}{1 - 0.7}$

$\rm \: = \: \: \dfrac{0.15}{0.30}$

$\rm \: = \: \: 0.5$