Maths · Statistics and probability · chapter 14 of 14
Class 11 Maths Chapter 14: Probability Assertion-reason questions with answers
2 assertion-reason questions on Probability, each with its answer and the reason, written from the NCERT chapter. For school exams on the CBSE pattern and JEE Main, which are set from the same NCERT chapter. Open a question's solution to check your working; then take the free test to find your next chapter. Each question gives an Assertion (A) and a Reason (R); choose how they stand to each other.
Question 1
Assertion (A): If P(not E) = 0.35, then P(E) = 0.65. Reason (R): E and E′ are mutually exclusive and exhaustive, so P(E) + P(E′) = 1.
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Answer: (a) Both A and R are true, and R is the correct explanation of A.
Both are true. P(E) = 1 – P(E′) = 1 – 0.35 = 0.65 follows directly from R.
Question 2
Assertion (A): When a die is thrown, the events 'an even number appears' and 'a prime number appears' are mutually exclusive. Reason (R): The simple events of a sample space are always mutually exclusive.
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Answer: (d) A is false, but R is true.
A is false: 2 is even and prime, so the two events can occur together. R is true, but neither event here is simple.