1use bayes' theorem
1 ) If each element of a second order determinant is either zero or one,what is the probability that the value of the determinant is positive? (Assume that the individual entries of the determinant are chosen independently,each value being assumed with probability 1/2).
2) Bag 1 contains 3 red and 4 black balls and Bag 2 contains 4 red and 5 black balls. One ball is transferred from Bag 1 to Bag 2 and then a ball is drawn from Bag 2.The ball so drawn is found to be red in colour. Find the probability that the transferred ball is black.
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4 Answers
62a b
c d
let the above b ethe determinant
its value will be
ad-bc
now for this to be +ve we have only one possiblity
ad=1, bc=0
so a=d=1 along with
b=c=0 or b=1, c=0 or b=0 , c=1
hence 3 ways to do this.
total ways is 24 = 16
hence 3/16
1arey second q toh txt buk mein solvd eg hai :P
woh bhi boards ki txt buk !!
