Consider the following argument: On Sundays, I go shopping. If I'm feeling tired, I don't go shopping. Therefore, if it is not Sunday, I'm feeling tired. Give answers and their derivation to the following: 1) Formulate propositional logic expressions of the above argument. 2) Using a truth table, decide and explain if the above argument is valid or not. 3) Without using the truth table, explain why the above argument is valid or not by applying methods of proof based on Modus Tollens