Directions (Q.1-4): Study the following information carefully to answer following information carefully to answer the questions.
Five boys and five girls are sitting in a row. Find the probability that
1.All the girls are sitting together.
(a)1/42
(b)41/42
(c)3/35
(d)1/42
(e)None of the above
2.All the boys are sitting together.
(a)3/42
(b)41/42
(c)3/35
(d)1/42
(e)None of the above
3.All the girls are not sitting together.
(a)41/42
(b)39/42
(c)31/42
(d)31/35
(e)None of the above
4.All the boys are not sitting together.
(a)3/35
(b)43/49
(c)41/42
(d)1/42
(e)None of the above
5.An elevator starts with 5 passengers and stops at 8 different floors of the house. Find out the probability of the all the 5 passengers alighting at different floors.
(a)101/512
(b)105/512
(c)107/512
(d)109/512
(e)None of the above
6.If a 4-digit number is formed at random using the digits 1, 3, 5, 7 and 9 without repetition, then the probability that it is divisible by 5, is
(a)4/5
(b)3/5
(c)1/5
(d)2/3
(e)None of the above
Direction (Q.7-8): Study the information carefully to answer the questions that follow.
A basket contains 3 blue, 2 green and 5 red balls.
7.If three balls picked at random, what is the probability that at least one is red?
(a)1/2
(b)7/12
(c)11/12
(d)1/5
(e)None of the above
8. If four balls are picked at random, what is the probability that two are green and two are blue?
(a)1/18
(b)1/70
(c)3/5
(d)1/2
(e) None of the above
9. Two persons A and B appear in an interview for two vacancies. If the probabilities of their selections are 1/4 and 1/6, respectively, then the probability that none of them is selected, is
(a)5/8
(b)5/12
(c)1/12
(d)1/24
(e)None of the above
10. The probabilities of solving a problem by three students. A, B and C are 1/2,1/3 and 1/4, respectively. The probability that the problem will be solved, is
(a)1/4
(b)1/2
(c)3/4
(d)1/3
(e)None of the above
Answers with Explanation !!!!!!!!!!!!!!!!!
