Previous GATE Questions in Discrete Mathematics

40 votes
5 answers
62
Consider the quadratic equation $x^2-13x+36=0$ with coefficients in a base $b$. The solutions of this equation in the same base $b$ are $x=5$ and $x=6$. Then $b=$ _____
57 votes
10 answers
63
Let $p, q, r$ denote the statements ”It is raining”, “It is cold”, and “It is pleasant”, respectively. Then the statement “It is not raining and it is pleas...
1 votes
1 answer
65
Consider the following well-formed formula:$\exists x \forall y [ \neg \: \exists z [ p (y, z) \wedge p (z, y) ] \equiv p(x,y)]$Express the above well-formed formula in c...
7 votes
3 answers
66
25 votes
2 answers
67
If the set $S$ has a finite number of elements, prove that if $f$ maps $S$ onto $S$, then $f$ is one-to-one.
1 votes
1 answer
68
2 votes
0 answers
69
1 votes
0 answers
70
15 votes
2 answers
71
Show that if $G$ is a group such that $(a. b)^2 = a^2.b^2$ for all $a, b$ belonging to $G$, then $G$ is an abelian.
15 votes
4 answers
72
13 votes
3 answers
73
31 votes
5 answers
74
25 votes
4 answers
75
Find the number of single valued functions from set $A$ to another set $B,$ given that the cardinalities of the sets $A$ and $B$ are $m$ and $n$ respectively.
0 votes
0 answers
76
Give one property of the field of real numbers which no longer holds when we compute using finite-precision floating point numbers.
20 votes
6 answers
77
37 votes
5 answers
78
How many substrings (of all lengths inclusive) can be formed from a character string of length $n$? Assume all characters to be distinct, prove your answer.
31 votes
4 answers
79
19 votes
7 answers
80