Fundamentals of Mathematics

In general, mathematical models used to simulate biological problems:
If $$p\vee q$$ is true and $$p\wedge q$$ is false, then which of the following is not true?
Why $$( p \wedge q ) \Rightarrow r$$ is true when p is true and q is false.
A mathematical expression written in the form of equation is represented as ____.
By using the principle of mathematical induction we can proove that $$n\left( {n + 1} \right)\left( {n + 5} \right)$$ is a multiple of $$3$$.