Answer to Question #297771 in Statistics and Probability for kool

Question

The chance that a student will clear the quiz-1 paper is 0.59 and the chance that he will clear both quiz-1 and quiz-2 papers is 0.17. The chance that he will clear at least one quiz paper is 0.74. What is the chance that he will clear quiz-2 paper?

Answer 1

$$P(1\cup 2)=P(1)+P(2)-P(1\cap 2)$$

Then

$$P(2)=P(1\cup 2)+P(1\cap 2)-P(1)$$

Substitute

$$P(2)=0.74+0.17-0.59=0.32$$

The chance that a student will clear quiz-2 paper is 0.32.