#### Answer

Truth table for (p $\rightarrow$ (q $\rightarrow$ r)) $\leftrightarrow$ ((p $\land$ q) $\rightarrow$ r):

#### Work Step by Step

First fill in the eight possible combinations of truth values for p, q, and r. Then valuate the if/then statement (q $\rightarrow$ r). When the if element is T and then element is F, the statement is F. In all other cases the statement is T. Next evaluate the if/then statement (p $\rightarrow$ (q $\rightarrow$ r)). Then evaluate the statement (p $\land$ q) according to the definition of AND (p $\land$ q is true when, and only when, both p and q are true. If either p or q is false, or if both are false, p $\land$ q is false). Next evaluate the if/then statement ((p $\land$ q) $\rightarrow$ r). Lastly evaluate the biconditional statement according to the definition of biconditional (a $\leftrightarrow$ b is true if both a and b have the same truth values and is false if a and b have opposite truth values).