Math for Computer science Questions and Answers 141 to 150

Math for Computer science

Questions  141 to 150

141.	All the members of a set A are indicated by dots on the number line as given below. A = (a) { x / x is an integer and –3 < x < 5 } (b) { x / x is an integer and –3 £ x £ 5 } (c) { x / x is an integer and –2 < x < 5 } (d) { x / x is an integer and –2 £ x < 6 } (e) { x / x is an integer and –2 £ x £ 6 }.
142.	The universal set is E and E = {Sun, Moon, Earth, Mars, Jupiter, Saturn, Neptune}. A = {Moon, Mars, Jupiter} and B = {Sun, Moon, Earth} Then, A È Bc is: (a) {Moon, Mars, Jupiter, Neptune} (b) {Mars, Jupiter} (c) {Moon, Mars, Jupiter, Saturn} (d) {Moon, Mars, Jupiter, Saturn, Neptune} (e) {Sun, Moon, Earth, Mars, Jupiter, Saturn, Neptune}.
143.	{x / x ÎR and x2 + 9 = 6x} equals: (a) {3} (b) {3, –3} (c) {3, 2} (d) {3, 21} (e) {3, 15}.
144.	Which of the following sets is null (i.e. empty)? (a) {x / x  Z and x > 0} (b) {x / x  N and 15 < x < 16 } (c) {x / x  Z and  –16  x  –15 } (d) {x / x  Z and x < –3 } (e) {x / x  N and x is prime, x is even}.
145.	Let A = {a, b, c}, B = {1, 2} and the function f : A →B be defined as f(a) = 1, f(b) = 2,       f(c) = 2. Which of the following statements is correct? (a) f is an onto function (b) f is a 1–1 function (c) f is not an onto function (d) f is not a function (e) f is a bijection.
146.	Consider the following venn diagram. The shaded portion in the Venn diagram represents (a) (Ac ∩ Bc)  ( Bc ∩ Cc)  (Cc ∩ Ac) (b) Ac Bc Cc (c) Ac ∩ Bc ∩Cc (d) (A ∩ Bc )  (B ∩Cc)  (C ∩Ac) (e) (Ac ∩ Cc)  ( Bc ∩Cc).
147.	If A = {(x, y) / x, y ∈R and x2 + y2 = 17} and B = {(x, y) / x, y ∈R and x + y = 5}, then,           A ∩B equals to (a) {4} (b) {1, 4} (c) {(1, 4)} (d) {(4, 1)} (e) {(1, 4), (4, 1)}.
148.	Let  and  which of the following is correct? (a) (b) (c) (d) (e)
149.	Which of the following sets of ordered pairs is a function defined on a set A= {1,2,3,4} (a) 2), (3, 1), (4, (b) 3), (2, 1), (2, 4), (3, 2), (4, (c) 3), (2, 4), (3, 1), (3, 2), (4, (d) 1), (2, 4), (4, (e) 4), (2, 3), (3, 2), (4,
150.	Given f : Z à R, where f(x) = |x|, for x Î Z. Which of the following statement is true about the range of f. (a) Range of f = Z (b) Range of  f = N (c) Range of  f = N È {0} (d) Range of  f = Z \ N (e) Range of f  = Z \ {–1, –2, –3, …….}.

Answers

141.	Answer : (d) Reason  :       by the definition set builder notation
142.	Answer : (d) Reason  :       by the definition set builder notation
143.	Answer : (a) Reason  :       by the definition set builder notation
144.	Answer : (b) Reason  :       by the definition of empty set
145.	Answer : (a) Reason  :       by the definition of onto function
146.	Answer : (c) Reason  :       by the definition of venn diagrams
147.	Answer : (e) Reason  :       by the definition of set builder notation constructing the sets and simplification A ∩ B =  {(1, 4), (4, 1)}
148.	Answer : (b) Reason  :       by the definition of composition of functions
149.	Answer : (e) Reason  :       by the definition of function
150.	Answer : (c) Reason  :       by the definition of function the Range of  f = N È {0}