Math Problem Statement

Let p be the proposition “You get an A on the final exam,” let q be the proposition “You did every exercise

in this book,” and let r be the proposition “You get an A in this class.” Write these propositions using 𝑝𝑝,

𝑞𝑞, and 𝑟𝑟 and logical connectives.

a) You get an A in this class but did not do every exercise in this book.

b) You get an A on the final, do every exercise in this book, and get an A in this class.

c) To get an A in this class, it is necessary for you to get an A on the final.

d) You get an A on the final but did not do every exercise in this book; nevertheless, you get an A in

this class.

e) Getting an A on the final and doing every exercise in this book is sufficient for getting an A in this

class.

Solution

Let's express each of these propositions using the symbols pp (you get an A on the final exam), qq (you did every exercise in this book), and rr (you get an A in this class), along with logical connectives.

a) You get an A in this class but did not do every exercise in this book.

This can be expressed as: r¬qr \land \neg q

b) You get an A on the final, do every exercise in this book, and get an A in this class.

This can be expressed as: pqrp \land q \land r

c) To get an A in this class, it is necessary for you to get an A on the final.

This can be expressed as: rpr \rightarrow p

d) You get an A on the final but did not do every exercise in this book; nevertheless, you get an A in this class.

This can be expressed as: p¬qrp \land \neg q \land r

e) Getting an A on the final and doing every exercise in this book is sufficient for getting an A in this class.

This can be expressed as: (pq)r(p \land q) \rightarrow r


Do you want details on any of these logical expressions, or do you have any questions?

Here are five questions that extend these concepts:

  1. How do we represent the logical expression for "If you did every exercise in the book, then you get an A on the final"?
  2. What is the contrapositive of the expression rpr \rightarrow p?
  3. How would you express "Getting an A in this class is sufficient for getting an A on the final and doing every exercise"?
  4. How can we represent "You did not get an A on the final and did every exercise in this book"?
  5. What is the converse of the statement (pq)r(p \land q) \rightarrow r?

Tip: When working with logical connectives, understanding the difference between "necessary" and "sufficient" conditions is crucial for accurate translation into logical expressions.