NCERT

In a hostel, 60 \% of the students read Hindi newspaper, 40 \% read English newspaper and 20 \% read both Hindi and English newspapers. A student is selected at random.
(a) Find the probability that she reads neither Hindi nor English newspapers.
(b) If she reads Hindi newspaper, find the probability that she reads English newspaper.
(c) If she reads English newspaper, find the probability that she reads Hindi newspaper

Given: The letters $H$ and $E$ stand for the number of students who read the Hindi newspaper and the English daily, respectively. Hence, $\mathrm{P}(\mathrm{H})=$ Probability of students who read...

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One card is drawn at random from a well shuffled deck of 52 cards. In which of the following cases are the events \mathrm{E} and \mathrm{F} independent?
(i) E: ‘the card drawn is a spade’ F: ‘the card drawn is an ace’
(ii) E: ‘the card drawn is black’ \mathrm{F} : ‘the card drawn is a king’
(iii) E: ‘the card drawn is a king or queen’ F: ‘the card drawn is a queen or jack’.

Solution: Given: A deck of 52 cards. Concept: Two events are independent, statistically independent, or stochastically independent if the occurrence of one does not affect the probability of...

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A box of oranges is inspected by examining three randomly selected oranges drawn without replacement. If all the three oranges are good, the box is approved for sale, otherwise, it is rejected. Find the probability that a box containing 15 oranges out of which 12 are good and 3 are bad ones will be approved for sale.

Solution: Given: A box of oranges. Let A, B, and C represent the events that occur when the first, second, and third drawn oranges are all excellent. Now, $P(A)=P$ (good orange in first draw) $=12 /...

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Q.There is a circular path around a sports field. Sonia takes 18 minutes to drive one round of the field, while Ravi takes 12 minutes for the same. Suppose they both start at the same point and at the same time, and go in the same direction. After how many minutes will they meet again at the starting point?

Since, Both Sonia and Ravi move in the same direction and at the same time,  The method to find the time when they will be meeting again at the starting point is LCM(Lowest Common Multiple) of 18...

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An instructor has a question bank consisting of 300 easy True / False questions, 200 difficult True / False questions, 500 easy multiple choice questions and 400 difficult multiple choice questions. If a question is selected at random from the question bank, what is the probability that it will be an easy question given that it is a multiple-choice question?

Solution: There are two sorts of questions in this section: True/False and Multiple Choice Questions (T/F or MCQ), and each of these types is further subdivided into Easy and Difficult categories,...

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