The chances to fail in Physis are 20% and the chances to fail in Mathematics are 10%. What are the chances to fail in atleast one subject ?

Options

A. 0.28
B. 0.38
C. 0.72
D. 0.82

Answer

A

Explanation

Let P `(A)=(20)/(100)=(1)/(5),P(B)=(10)/(100)=(1)/(10)`
Since, event are independent and we have to find `P(AuuB)=P(A)+P(B)-P(A)*P(B)`
`=(1)/(5)+(1)/(10)-(1)/(5)*(1)/(10)`
`=(3)/(10)-(1)/(50)=(14)/(50)=(14)/(50)xx100=28%`