#### Answer

Argument is Valid.

#### Work Step by Step

An argument consists of two parts which are called the premises and a conclusion. An argument is called valid argument if conclusion is true whenever the premises are assumed to be true.
Consider the simple statements in the argument with a letter:
\[p\]: I am sick.
\[q\]: I am tired.
Express the premises and the conclusion symbolically as
I am sick or I am tired: \[p\vee q\]
\[\frac{\text{ I am not tired}}{\therefore \text{I am sick}\text{.}}\]: \[\frac{\tilde{\ }q}{\therefore p}\]
Write a symbolic statement of the following form:
\[\left[ \left( \text{premise}\ \text{1} \right)\wedge \left( \text{premise}\ \text{2} \right) \right]\to \text{conclusion}\]
The symbolic statement is
\[\left( p\vee q \right)\wedge \left( \tilde{\ }q \right)\to p\]