# NCERT Class 11-Math's: Exemplar Chapter –16 Probability Part 10

Glide to success with Doorsteptutor material for ISAT : Get full length tests using official NTA interface: all topics with exact weightage, real exam experience, detailed analytics, comparison and rankings, & questions with full solutions.

**Question 23:**

(A)

(B)

(C)

(D) None of these

**Answer: (A)**

**Question 24:**

If for any two events A and B, then

(A)

(B)

(C)

(D) None of these

**Answer: (A)**

**Question 25:**

boys and girls sit in a row at random. The probability that all the girls sit together is

(A)

(B)

(C)

(D) None of these

**Answer: (C)**

**Question 26:**

A single letter is selected at random from the word ‘PROBABILITY’. The probability that it is a vowel is

(A)

(B)

(C)

(D)

**Answer: (B)**

**Question 27:**

If the probabilities for A to fail in an examination is and that for B is , then the probability that either A or B fails is

(A)

(B)

(C)

(D)

**Answer: (C)**

**Question 28:**

The probability that at least one of the events A and B occurs is 0.6. If A and B occur simultaneously with probability , then is

(A)

(B)

(C)

(D)

**Answer: (C)**

**Question 29:**

If M and N are any two events, the probability that at least one of them occurs is

(A)

(B)

(C)

(D)

**Answer: (B)**

## State Whether the Statements Are True or False in Each of the Exercises 30 to 36

**Question 30:**

The probability that a person visiting a zoo will see the giraffe is , the probability that he will see the bears is and the probability that he will see both is .

**Answer: False**

**Question 31:**

The probability that a student will pass his examination is , the probability of the student getting a compartment is , and the probability that the student will either pass or get compartment is .

**Answer: False**

**Question 32:**

The probabilities that a typist will make or more mistakes in typing a report are, respectively, .

**Answer: False**