Use symbols to write the logical form the argument given below and then determine whether or not it is a valid argument:

1. Use symbols to write the logical form the argument given below and then determine whether or not it is a valid argument: If Henry ate his lunch, then Henry is not hungry ∴ Henry is hungry

2. Use a truth table to determine whether the following argument is valid.   p →q ∨ ∼r   q → p ∧ r ∴ p →r

3. Using the valid argument forms, show that the argument is valid:

~p ∧ q r → p ~r → s s → t ∴t