Q9 of 54 Page 314

In a class, 40% of the students participated in Mathematics-quiz, 30% in Science-quiz and 10% in both the quiz programmes. If a student is selected at random from the class, find the probability that the student participated in Mathematics or Science or both quiz programmes.

Let the probability of students participating in mathematics be P(A) ad that in science be P(B).


P(A) = 0.4


P(B) = 0.3


P (A ∩B) = 0.1


P(AUB) = P(A)+P(B)- P(A ∩B)


= 0.4+0.3-0.1


= 0.6



Thus the probability is


More from this chapter

All 54 →
7

Two dice are rolled simultaneously. Find the probability that the sum of the numbers on the faces is neither divisible by 3 nor by 4.

 8

A basket contains 20 apples and 10 oranges out of which 5 apples and 3 oranges are rotten. If a person takes out one fruit at random, find the probability that the fruit is either an apple or a good fruit.

 10

A card is drawn at random from a well-shuffled deck of 52 cards. Find the probability that it will be a spade or a king.

 11

A box contains 10 white, 6 red and 10 black balls. A ball is drawn at random. Find the probability that the ball drawn is white or red.