Which of the following statements is a tautology?

The negation of the statement "All continuous functions are differentiable" is:

The maximum number of compound propositions,out of $p \vee r \vee s$,$p \vee \sim r \vee \sim s$,$p \vee \sim q \vee s$,$\sim p \vee \sim r \vee s$,$\sim p \vee \sim r \vee \sim s$,$\sim p \vee q \vee \sim s$,$q \vee r \vee \sim s$,$q \vee \sim r \vee \sim s$,$\sim p \vee \sim q \vee \sim s$ that can be made simultaneously true by an assignment of the truth values to $p, q, r$ and $s$,is equal to

Consider the statement "The match will be played only if the weather is good and the ground is not wet". Select the correct negation from the following:

The negation of the statement $p \rightarrow (q \wedge r)$ is equal to .........

If $q$ is false and $p \wedge q \leftrightarrow r$ is true,then which of the following is a tautology?