Question

Events A and B are independent. Find the missing probability. Enter your answer as a decimal rounded to two places.

P(A)= 2/5, P( A and B) = 3/10, P(not B)= ?

Answer 1

`P(not \: B) = (1)/(4)`

Step-by-step explanation

If A and B are independent events, then

P(A and B)=P(A)×P(B)

`(3)/(10) = (2)/(5) * \: P(B)`

Multiply both sides by;

`(5)/(2)`

`(5)/(2) * (3)/(10) = (5)/(2) * (2)/(5) * \: P(B)`

`(3)/(4) =P(B)`

`P(not \: B) = 1 - P(B)`

`P(not \: B) = 1 - (3)/(4)`

`P(not \: B) = (1)/(4)`