Probability Tes...

If $$A, B$$ and $$C$$ are mutually exclusive and exhaustive events, then $$P(A) + P(B) + P(C)$$ equals to - 

$$A, B$$ and $$C$$ are three mutually exclusive and exhaustive events such that $$P(A) = 2 P(B) = 3P(C)$$. What is $$P(B)$$?

An urn contains $$10$$ balls coloured either black or red When selecting two balls from the urn at random, the probability that a ball of each color is selected is $$8/15$$. Assuming that the urn contains more black balls then red balls, the probability that at least one black ball is selected, when selecting two balls, is

Bag $$A$$ contains $$2$$ white and $$3$$ red balls and bag $$B$$ contains $$4$$ white and $$5$$ red balls. One ball is drawn at random from one of the bag is found to be red. Find the probability that it was drawn from bag $$B$$.

If $$P(A)=0.40,P(B)=0.35$$ and $$P\left( A\cup B \right) =0.55$$, then $$P(A/B)=$$ ____

If $$A$$ and $$B$$ are mutually exclusive events, then

An experiment is known to be random if the results of the experiment -

If A and B are two independent events such that $$P\left( A \right) = \dfrac{1}{2}$$ and $$P\left( B \right) = \dfrac{1}{5}$$, then 

Two unbiased dice are thrown. The probability that the sum of the numbers appearing on the top face of two dice is greater than $$7$$ if $$4$$ appear on the top face of the first dice is...

There are six letters $$L_1, L_2, L_3, L_4, L_5, L_6$$ are their corresponding six envelopes $$E_1, E_2, E_3, E_4, E_5, E_6$$. Letters having odd value can be put into odd value envelopes and even value letters can be put into even value envelopes, so that no letter go into the right envelopes, then number of arrangement equals?