JEE MATHEMATICS MCQ: PROBABILITY

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In a test an examinee either guesses, copies or knows the answer to multiple choice question with five choices. The probability that he makes a guess is

\frac{1}{4}

and probability that he copies the answer is

\frac{1}{8}

. The probability that his answer is correct given that he copies is

\frac{1}{10}

. Find the probability that he knows the answer to the question given that he correctly answered it:

View answer and explanation

Correct option: B

\frac{10}{11}

Option B (

\frac{10}{11}

) is correct because it is the probability that the examinee knows the answer given that he answered correctly, calculated using Bayes' theorem.

More Questions from PROBABILITY

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Consider the probability distribution

\begin{array}{cccccc}X: & 1 & 2 & 3 & 4 & 5 \\ P(X): & k^2 & 2 k & k & 2 k & 5 k^2\end{array}

The value of

P(X>2)

is A bag contains

\left( {2\;n + 1} \right)

coins. It is known that

n

of these coins have a head on both sides, whereas the remaining

n + 1

coins are fair. A coin is picked up at random from the bag and tossed. If the probability that the toss results in a head is 31/42, then

n

is equal to The probability that a bulb produced by a factory will fuse after 150 days of use is 0.05 . What is the probability that out of 5 such bulbs none will fuse after 150 days of use If

A

and

B

are two independent events such that

P\left( {A \cap B'} \right) = \frac{3}{{25}}

and

P\left( {A' \cap B} \right) = \frac{8}{{25}}

, then

P\left( A \right)

is equal to In a game two players

A

and

B

take turns in throwing a pair of fair dice starting with player

A

and total of scores on the two dice, in each throw is noted. A wins the game if he throws a total of 6 before

B

throws a total of 7 and

B

wins the game if he throws a total of 7 before A throws a total of six. The game stops as soon as either of the player wins. The probability of

A

winning the game is A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same colour is