Probability Tes...

An arrangement is selected at random from all possible arrangements of five digits written from the digits $$0,1,2,3,\cdots 9$$ with repetition. The probability that the randomly selected arrangement will have largest number $$'8'$$ given that the smallest number is $$'4'$$ is :

Result of each experiment is called 

Cards are dealt one by one from a well shuffled pack until an ace appears. the probability that exactly n cards are dealt befor  the first ace appears is

There are two balls in an urn whose colors are not known ( ball can be either white or black). A white ball is put into the urn. A ball is then drawn from the urn. The probability that it is white is 

A man is know to speak the truth $$3$$ out of $$4$$ times. He throws a die and reports that it is a six. the probability that it is actually a six is

The chances of defective screws in three boxes A, B and C are $$\dfrac {1}{5}, \dfrac {1}{6}, \dfrac {1}{7}$$ respectively. A box is selected at random and a screw drawn from it at random, is found to be defective. The probability that it came from the box 'A' is

A letter is known to have come either from $$TATANAGAR$$ or $$CALCUTTA$$. On the envelope just two consecutive letters $$TA$$ are visible. What is the probability that the letter came from $$CALCUTTA$$?

Three groups $$A,\ B,\ C$$ are contesting for positions on the Board of Directors of a company. The probabilities of their winning are $$0.5,\ 0.3, 0.2$$ respectively. If the group $$A$$ wins, the probability of introducing a new product is $$0.7$$ and the corresponding probabilities for groups $$B$$ and $$C$$ are $$0.6$$ and $$0.5$$ respectively. The probability that the new product will be introduced is given by

A letter is known to have come either from $$TATANAGAR$$ or $$CALCUTTA$$. On the envelope just two consecutive letters $$TA$$ are visible. What is the probability that the letter came from $$TATANAGAR$$?

The chance that Doctor A will diagonise disease X correctly is $$60\%$$. The chance that a patient will die by his treatment after correct diagnosis is $$40\%$$ and the chance of death after wrong diagnosis is $$70\%.$$ A patient of Doctor A who had disease X died. The probability that his disease was diagonised correctly is