Chapter 5: Problem 2
Show that if eight people are in a room, at least two of them have birthdays that occur on the same day of the week.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 5: Problem 2
Show that if eight people are in a room, at least two of them have birthdays that occur on the same day of the week.
All the tools & learning materials you need for study success - in one app.
Get started for free
During the first six weeks of his senior year in college, Brace sends out at least one resumé each day but no more than 60 resumés in total. Show that there is a period of consecutive days during which he sends out exactly 23 resumés.
The following Pascal program segment implements an algorithm for determining the maximum value in an array \(A[1], A[2], A[3], \ldots, A[n]\) of integers. The array and the value of \(n(\geq 2)\) are supplied earlier in the program; the integer variables \(i\) and Max are declared at the start of the program. (Here the entries in the array need not be distinct) Begin \(\mathrm{Max}:=\mathrm{A}[1]\) For \(1:=2\) to \(n\) do If \(A[1]>M a x\) then Max : = A[1] End; a) If the worst-case complexity function \(f(n)\) for this segment is determined by the number of times the comparison \(A[i]>\mathrm{Max}\) is executed, find the appropriate "big-Oh" form for \(f\). b) What can we say about the best-case and average-case complexities for this implementation?
Let \(f: \mathbf{Z} \rightarrow \mathbf{N}\) be defined by $$ f(x)= \begin{cases}2 x-1, & \text { if } x>0 \\ -2 x, & \text { for } x \leq 0\end{cases} $$ a) Prove that \(f\) is one-to-one and onto. b) Determine \(f^{-1}\).
For \(\emptyset \neq A \subseteq \mathbf{Z}^{+}\), let \(f, g: A \times A \rightarrow A\) be the closed binary operations defined by \(f(a, b)=\) \(\min \\{a, b\\}\) and \(g(a, b)=\max \\{a, b\\}\). Does \(f\) have an identity element? Does \(g\) ?
If \(\mathcal{U}\) is a given universe with (fixed) \(S, T \subseteq \varkappa\), define \(g: \mathscr{P}(\mathcal{Q}) \rightarrow \mathscr{P}(\mathcal{U})\) by \(g(A)=\) \(T \cap(S \cup A)\) for \(A \subseteq U\). Prove that \(g^{2}=g\).
What do you think about this solution?
We value your feedback to improve our textbook solutions.