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Recent questions tagged kenneth-rosen
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451
Kenneth Rosen Edition 7 Exercise 6.1 Question 1 (Page No. 396)
There are $18$ mathematics majors and $325$ computer science majors at a college. In how many ways can two representatives be picked so that one is a mathematics major and the other is a computer science major? In how many ways can one representative be picked who is either a mathematics major or a computer science major?
There are $18$ mathematics majors and $325$ computer science majors at a college.In how many ways can two representatives be picked so that one is a mathematics major and...
admin
6.9k
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admin
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Apr 23, 2020
Combinatory
kenneth-rosen
discrete-mathematics
counting
descriptive
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1
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2
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452
Kenneth Rosen Edition 7 Exercise 2.5 Question 40 (Page No. 177)
Show that if $S$ is a set, then there does not exist an onto function $f$ from $S$ to $P(S),$ the power set of $S$. Conclude that $\mid S\mid < \mid P(S)\mid .$ This result is known as Cantor's theorem. [Hint: Suppose such a function ... $s$ can exist for which $f (s) = T.]$
Show that if $S$ is a set, then there does not exist an onto function $f$ from $S$ to $P(S),$ the power set of $S$. Conclude that $\mid S\mid < \mid P(S)\mid .$ This res...
admin
660
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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453
Kenneth Rosen Edition 7 Exercise 2.5 Question 39 (Page No. 177)
We say that a function is computable if there is a computer program that finds the values of this function. Use question $37$ and $38$ to show that there are functions that are not computable.
We say that a function is computable if there is a computer program that finds the values of this function. Use question $37$ and $38$ to show that there are functions th...
admin
251
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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1
votes
1
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454
Kenneth Rosen Edition 7 Exercise 2.5 Question 38 (Page No. 177)
Show that the set of functions from the positive integers to the set $\{0, 1, 2, 3, 4, 5, 6, 7, 8, 9\}$ is uncountable. [Hint: First set up a one-to-one correspondence between the set of real numbers between $0$ and $1$ and a subset of ... to the real number $0.\:d_{1}d_{2} \dots d_{n}\dots $ the function $f$ with $f (n) = dn.]$
Show that the set of functions from the positive integers to the set $\{0, 1, 2, 3, 4, 5, 6, 7, 8, 9\}$ is uncountable. [Hint: First set up a one-to-one correspondence be...
admin
710
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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455
Kenneth Rosen Edition 7 Exercise 2.5 Question 37 (Page No. 177)
Show that the set of all computer programs in a particular programming language is countable. [Hint: A computer program written in a programming language can be thought of as a string of symbols from a finite alphabet.]
Show that the set of all computer programs in a particular programming language is countable. [Hint: A computer program written in a programming language can be thought o...
admin
269
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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456
Kenneth Rosen Edition 7 Exercise 2.5 Question 36 (Page No. 177)
Show that there is a one-to-one correspondence from the set of subsets of the positive integers to the set real numbers between $0$ and $1$. Use this result and question $34$ and $35$ to conclude that $ℵ_{0} < \mid P(Z^{+})\mid =\mid R\mid.\:[$Hint: Look at the first part of the hint for Exercise $35.]$
Show that there is a one-to-one correspondence from the set of subsets of the positive integers to the set real numbers between $0$ and $1$. Use this result and question ...
admin
257
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
answers
457
Kenneth Rosen Edition 7 Exercise 2.5 Question 35 (Page No. 177)
Show that there is no one-to-one correspondence from the set of positive integers to the power set of the set of positive integers. [Hint: Assume that there is such a one-to-one correspondence. Represent a subset of the set of ... $ith$ string in the list. Show that this new bit string cannot appear in the list.]
Show that there is no one-to-one correspondence from the set of positive integers to the power set of the set of positive integers. [Hint: Assume that there is such a one...
admin
244
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
votes
0
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458
Kenneth Rosen Edition 7 Exercise 2.5 Question 34 (Page No. 177)
Show that $(0, 1)$ and $R$ have the same cardinality. [Hint: Use the Schröder-Bernstein theorem.]
Show that $(0, 1)$ and $R$ have the same cardinality. [Hint: Use the Schröder-Bernstein theorem.]
admin
194
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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459
Kenneth Rosen Edition 7 Exercise 2.5 Question 33 (Page No. 177)
Use the Schröder-Bernstein theorem to show that $(0, 1)$ and $[0, 1]$ have the same cardinality.
Use the Schröder-Bernstein theorem to show that $(0, 1)$ and $[0, 1]$ have the same cardinality.
admin
199
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
answers
460
Kenneth Rosen Edition 7 Exercise 2.5 Question 32 (Page No. 177)
Show that when you substitute $(3n + 1)^{2}$ for each occurrence of $n$ and $(3m + 1)^{2}$ for each occurrence of m in the right-hand side of the formula for the function $f (m, n)$ in question $31,$ you ... $Q \times Q \rightarrow Q.$
Show that when you substitute $(3n + 1)^{2}$ for each occurrence of $n$ and $(3m + 1)^{2}$ for each occurrence of m in the right-hand side of the formula for the function...
admin
197
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
votes
0
answers
461
Kenneth Rosen Edition 7 Exercise 2.5 Question 31 (Page No. 177)
Show that $Z^{+} \times Z^{+}$ is countable by showing that the polynomial function $f : Z^{+} \times Z^{+}\rightarrow Z^{+}$ with $f(m, n) = \dfrac{(m + n − 2)(m + n − 1)}{2} + m$ is one-to one and onto.
Show that $Z^{+} \times Z^{+}$ is countable by showing that the polynomial function $f : Z^{+} \times Z^{+}\rightarrow Z^{+}$ with $f(m, n) = \dfrac{(m + n − 2)(m + n �...
admin
222
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
votes
0
answers
462
Kenneth Rosen Edition 7 Exercise 2.5 Question 30 (Page No. 177)
Show that the set of real numbers that are solutions of quadratic equations $ax^{2} + bx + c = 0,$ where $a, b,$ and $c$ are integers, is countable.
Show that the set of real numbers that are solutions of quadratic equations $ax^{2} + bx + c = 0,$ where $a, b,$ and $c$ are integers, is countable.
admin
214
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
answers
463
Kenneth Rosen Edition 7 Exercise 2.5 Question 29 (Page No. 177)
Show that the set of all finite bit strings is countable.
Show that the set of all finite bit strings is countable.
admin
156
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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464
Kenneth Rosen Edition 7 Exercise 2.5 Question 28 (Page No. 177)
Show that the set $Z^{+} \times Z^{+}$ is countable.
Show that the set $Z^{+} \times Z^{+}$ is countable.
admin
170
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admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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465
Kenneth Rosen Edition 7 Exercise 2.5 Question 27 (Page No. 177)
Show that the union of a countable number of countable sets is countable.
Show that the union of a countable number of countable sets is countable.
admin
196
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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466
Kenneth Rosen Edition 7 Exercise 2.5 Question 26 (Page No. 177)
Use question $25$ to provide a proof different from that in the text that the set of rational numbers is countable. [Hint: Show that you can express a rational number as a string of digits with a slash and possibly a minus sign.]
Use question $25$ to provide a proof different from that in the text that the set of rational numbers is countable. [Hint: Show that you can express a rational number as ...
admin
258
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
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0
answers
467
Kenneth Rosen Edition 7 Exercise 2.5 Question 25 (Page No. 177)
Prove that if it is possible to label each element of an infinite set $S$ with a finite string of keyboard characters, from a finite list characters, where no two elements of $S$ have the same label, then $S$ is a countably infinite set.
Prove that if it is possible to label each element of an infinite set $S$ with a finite string of keyboard characters, from a finite list characters, where no two element...
admin
245
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
468
Kenneth Rosen Edition 7 Exercise 2.5 Question 24 (Page No. 177)
Show that there is no infinite set $A$ such that $\mid A \mid < \mid Z^{+} \mid = ℵ_{0}.$
Show that there is no infinite set $A$ such that $\mid A \mid < \mid Z^{+} \mid = ℵ_{0}.$
admin
195
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admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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469
Kenneth Rosen Edition 7 Exercise 2.5 Question 23 (Page No. 177)
Show that if $A$ is an infinite set, then it contains a countably infinite subset.
Show that if $A$ is an infinite set, then it contains a countably infinite subset.
admin
205
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
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470
Kenneth Rosen Edition 7 Exercise 2.5 Question 22 (Page No. 177)
Suppose that $A$ is a countable set. Show that the set $B$ is also countable if there is an onto function $f$ from $A$ to $B.$
Suppose that $A$ is a countable set. Show that the set $B$ is also countable if there is an onto function $f$ from $A$ to $B.$
admin
218
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admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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0
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0
answers
471
Kenneth Rosen Edition 7 Exercise 2.5 Question 21 (Page No. 177)
Show that if $A, B,$ and $C$ are sets such that $\mid A\mid \leq \mid B \mid $ and $\mid B \mid \leq \mid C\mid ,$ then $\mid A\mid \leq \mid C \mid .$
Show that if $A, B,$ and $C$ are sets such that $\mid A\mid \leq \mid B \mid $ and $\mid B \mid \leq \mid C\mid ,$ then $\mid A\mid \leq \mid C \mid .$
admin
187
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
472
Kenneth Rosen Edition 7 Exercise 2.5 Question 20 (Page No. 177)
Show that if $\mid A \mid = \mid B \mid $ and $\mid B \mid = \mid C\mid ,$ then $\mid A\mid =\mid C\mid .$
Show that if $\mid A \mid = \mid B \mid $ and $\mid B \mid = \mid C\mid ,$ then $\mid A\mid =\mid C\mid .$
admin
187
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
473
Kenneth Rosen Edition 7 Exercise 2.5 Question 19 (Page No. 177)
Show that if $A, B, C,$ and $D$ are sets with $ \mid A \mid = \mid B\mid $ and $\mid C\mid =\mid D\mid ,$ then $\mid A \times C \mid = \mid B \times D\mid .$
Show that if $A, B, C,$ and $D$ are sets with $ \mid A \mid = \mid B\mid $ and $\mid C\mid =\mid D\mid ,$ then $\mid A \times C \mid = \mid B \times D\mid .$
admin
196
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
474
Kenneth Rosen Edition 7 Exercise 2.5 Question 18 (Page No. 177)
Show that if $A$ and $B$ are sets $\mid A \mid = \mid B \mid ,$ then $\mid P(A) \mid = \mid P(B)\mid.$
Show that if $A$ and $B$ are sets $\mid A \mid = \mid B \mid ,$ then $\mid P(A) \mid = \mid P(B)\mid.$
admin
178
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admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
–
0
votes
0
answers
475
Kenneth Rosen Edition 7 Exercise 2.5 Question 17 (Page No. 176)
If $A$ is an uncountable set and $B$ is a countable set, must $A − B$ be uncountable?
If $A$ is an uncountable set and $B$ is a countable set, must $A − B$ be uncountable?
admin
255
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
–
0
votes
0
answers
476
Kenneth Rosen Edition 7 Exercise 2.5 Question 16 (Page No. 176)
Show that a subset of a countable set is also countable.
Show that a subset of a countable set is also countable.
admin
182
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
477
Kenneth Rosen Edition 7 Exercise 2.5 Question 15 (Page No. 176)
Show that if $A$ and $B$ are sets, $A$ is uncountable, and $A \subseteq B,$ then $B$ is uncountable
Show that if $A$ and $B$ are sets, $A$ is uncountable, and $A \subseteq B,$ then $B$ is uncountable
admin
201
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
–
0
votes
0
answers
478
Kenneth Rosen Edition 7 Exercise 2.5 Question 14 (Page No. 176)
Show that if $A$ and $B$ are sets with the same cardinality, then $\mid A \mid \leq \mid B \mid $ and $\mid B \mid \leq \mid A\mid.$
Show that if $A$ and $B$ are sets with the same cardinality, then $\mid A \mid \leq \mid B \mid $ and $\mid B \mid \leq \mid A\mid.$
admin
193
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
479
Kenneth Rosen Edition 7 Exercise 2.5 Question 13 (Page No. 176)
Explain why the set $A$ is countable if and only if $\mid A \mid \leq \mid Z^{+}\mid.$
Explain why the set $A$ is countable if and only if $\mid A \mid \leq \mid Z^{+}\mid.$
admin
181
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
+
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0
votes
0
answers
480
Kenneth Rosen Edition 7 Exercise 2.5 Question 12 (Page No. 176)
Show that if $A$ and $B$ are sets and $A \subset B$ then $\mid A \mid \leq \mid B\mid.$
Show that if $A$ and $B$ are sets and $A \subset B$ then $\mid A \mid \leq \mid B\mid.$
admin
170
views
admin
asked
Apr 21, 2020
Set Theory & Algebra
kenneth-rosen
discrete-mathematics
set-theory&algebra
descriptive
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