Mohan post a letter to Sohan. It is known that one letter out of `10 `letters do not reach its destination. If it is certain that Sohan will reply if he receives the letter. If `A` denotes the event that the Sohan receives the letter and `B` denotes the event that Mohan gets a reply, then

Options

A. `P(B)=(81)/(100)`
B. `P(AnnB)=(81)/(100)`
C. `P((A)/(barB))=(9)/(19)`
D. `P(AuuB)=(9)/(10)`

Answer

A, B, C, D

Explanation

`(a,b,c,d)` `P(A)=(9)/(10)`
`P(B)=P(AnnB)=(9)/(10)xx(9)/(10)=(81)/(100)`
`P((A)/(B))=(P(AnnbarB))/(P(barB))=((9)/(10)xx(1)/(10))/(1-(81)/(100))=(9)/(19)`
`P(AuuB)=P(A)+P(B)-P(AnnB)=(9)/(10)`