Elective Mathematics

1A bag has 4 red and 6 green balls. Two are picked one after the other without replacement. Find the probability that both are red.

2A binomial distribution has n = 10 and p = 0.3. Its mean is

3A bag contains 5 red and 3 blue balls. Two are drawn with replacement. P(both blue) is

4The mean of x, 2x, 3x is 8. Find x.

5P(A) = 0.4, P(B) = 0.5 and P(A ∪ B) = 0.7. Find P(A | B).

6P(A) = 0.6, P(B) = 0.5 and A, B independent. Find P(A ∪ B).

7If P(A) = 0.5, P(B) = 0.4 and A, B are independent, P(A ∪ B) is

8A fair die is thrown 3 times. P(at least one six) is

9Events A and B are independent with P(A) = 0.5 and P(B) = 0.4. Find P(A ∩ B).

10In how many ways can 4 boys and 3 girls sit in a row if the girls must sit together?