Re: Maths ! help !

Posted by Granpa Simpson on Apr 19, 2014; 9:00am
URL: http://discussion-forum.276.s1.nabble.com/Maths-help-tp7587407p7587432.html

Consider two equally likely events A & B s.t.
A= accident occurs in the first year.
B= accident occurs in the second year.
Also AUB= S
Now A and B are mutually exclusive as if accident occurs in year 1 then it cannot occur in year 2 and vice versa. Hence occurance of one event prevents occurance of the other hence mutually exclusive.
Now P(AUB) = P(A)+P(B)
again 1= P(A)+P(B),
if A and B are equally likely then P(A)=P(B)=1/2
Using this you will get the answer as 0.25.