# Math for Computer science Questions and Answers 151 to 160

## Math for Computer science

### Questions  151 to 160

151.
Let A = {a, b} and B be the set of all strings over A. The function g: B →Z is defined as            g(S) = the number of a’s in S, for each string S ∈B. Then g (ababb) =
 (a) 0 (b) 2 (c) 3 (d) 4 (e) 5
152.
How many different permutations can be formed out of all the letters of the word “MATHS”?
 (a) 12 (b) 24 (c) 20 (d) 120 (e) 60
153.
How many different permutations can be formed out of the letters of the word “MISSISSIPPI”?
 (a) (11!) / (7!) (b) (11!) / (3!) (c) (11!) / (2!. 4!. 4!) (d) (11!) / (4!) (e) (11!)/(4!. 3!).
154.
How many groups of 4 people can be formed from 6 people?
 (a) 15 (b) 30 (c) 60 (d) 120 (e) 45
155.
How many ways can 5 persons arrange themselves around a circular table?
 (a) 120 (b) 24 (c) 5 (d) 720 (e) 60
156.
Ten balls numbered 0, 1, 2, ….., 9 are put in a box and two balls are taken at random without replacement. The  probability that both numbers are odd is equal to
 (a) (b) (c) (d) (e) 1.
157.
A box contains 4 red balls and 2 white balls. Another box contains 5 red balls and 3 white balls. Abox is selected at random and then a ball is drawn at random. The probability that the ball is white is equal to
 (a) (b) (c) (d) (e) 0.
158.
If A and B be two events with P(A) = , P(B) =   and P(A È B) = , then P(A/B) =
 (a) (b) (c) 0 (d) (e) .
159.
If A and B be two events with P(A) = , P(B) =  and P(A Ç B) = , then P(Ac Ç Bc) =
 (a) (b) (c) (d) (e) .
160.
It is given that p → q, q → r and r → s are true. Which of the following must be necessarily true?
 (a) q → p (b) p → r (c) s → r (d) p → s (e) q → s.