NCERT Solutions for Class 12 Maths Chapter 13 Exercise 13.3 Limits and Derivatives is prepared by the academic team of Physics Wallah. We have prepared NCERT Solutions for all exercises of Chapter 13. Below is step by step solutions to all questions given in the NCERT Solutions for Class 12 Maths Chapter 13 Exercise 13.3 Limits and Derivatives.
NCERT Solutions for Class 12 Maths Chapter 13 Miscellaneous Exercise
Solve The Following Questions of NCERT Solutions for Class 12 Maths Chapter 13 Exercise 13.3:
Question 1. An urn contains 5 red and 5 black balls. A ball is drawn at random, its colour is noted and is returned to the urn. Moreover, 2 additional balls of the colour drawn are put in the urn and then a ball is drawn at random. What is the probability that the second ball is red? Solution : The urn contains 5 red and 5 black balls. Let a red ball be drawn in the first attempt. ∴ P (drawing a red ball) = 5/10 = 1/2 If two red balls are added to the urn, then the urn contains 7 red and 5 black balls. P (drawing a red ball) = 7/12 Let a black ball be drawn in the first attempt. ∴ P (drawing a black ball in the first attempt) = 5/10 = 1/2 If two black balls are added to the urn, then the urn contains 5 red and 7 black balls. P (drawing a red ball) = 5/12 Therefore, probability of drawing second ball as red isNCERT Solutions for Class 12 Maths Chapter 13 Exercise 13.1
Question 4. In answering a question on a multiple choice test a student either knows the answer or guesses. Let 3/4 be the probability that he knows the answer and 1/4 be the probability that he guesses. Assuming that a student who guesses the answer, will be correct with probability 1/4. What is the probability that a student knows the answer given that he answered it correctly?NCERT Solutions for Class 12 Maths Chapter 13 Exercise 13.5
Question 5. A laboratory blood test is 99% effective in detecting a certain disease when it is, in fact, present. However, the test also yields a false positive result for 0.5% of the healthy person tested (i.e., if a healthy person is tested, then, with probability 0.005, the test will imply he has the disease). If 0.1 percent of the population actually has the disease, what is the probability that a person has the disease given that his test result is positive?