Please help me with these problems. Thank you in advance

Rewrite so that there is no negation outside a quantifier (all are on predicates). What is wrong with this argument? Let S(x, y) be "x is shorter than y." Given the premise (s, Max) (where Max is the largest possible value), it follows that S(Max, Max). Then by existential generalization it follows that xs(x, x), so that someone is shorter than themself. Show that at least three of any 25 days chosen must fall in the same month of the year. Prove or disprove that if a and b are rational numbers, then a^b is also rational