Step 1:

The probability of event is $\"\"$ is $\"\"$ .

The probability of event is $\"\"$ is $\"\"$ . $\"\"$

Let the two events $\"\"$ and $\"\"$ are independent events, $\"\"$ .

Apply formula : $\"\"$ .

Substitute $\"\"$ , $\"\"$ and $\"\"$ .

$\"\"$

$\"\"$ .