can anyone please help me with question3 please ? I am stuck on it

3. Using a truth table, show which of the following sets of formula are satisfiable. Be sure to state your justification for your conclusion. a. {((pq)r),(pq),p} b. {(pq),p,q} c. {p,(qp),(qp)} a. (pq)(qp) b. k(pq)r)r c. ((pq)r)r 3. Using a truth table, show which of the following sets of formula are satisfiable. Be sure to state your justification for your conclusion. a. {((pq)r),(pq),p} b. {(pq),p,q} c. {p,(qp),(qp)} 4. Prove the following by mathematical induction. i=1ni2=6n(n+1)(2n+1) 5. Prove the following by mathematical induction: n!>2n for all integers n