I need help with discrete math

Fred is a math major or Fred is a business major. If Fred is a math major, then Fred will take Discrete Math Fred is a business major or Fred will not take Discrete Math. If one of these two numbers is divisible by 10, then the product of these two numbers is divisible by 10. Neither of these two numbers is numbers is divisible by 10. . The product of these two numbers is not divisbile by 10. If I get a raise, I'llgo on vacation. If I win the lottery, I'Tlgo on vacation. If I get a raise or win the lottery, I'llgo on vacation. 3.5 (a) Give an example of a valid argument with a false conclusion. (b) Give an example of an invalid argument with a true conclusion