On a separate sheet of paper (or computer software program like Word) construct a truth table proof of validit

Question

On a separate sheet of paper (or computer software program like Word) construct a truth table proof of validity for the following argument.
(H * J) > R
H * J
:R

Then answer the following questions based on your work and number each response so I can be sure of which question you are answering:
1. How many variables are involved in the proof?
2. How many rows do you need to complete the proof?
3. What rows have all true premises?
4. What are the truth values for the fourth row of the proof for each premise and the conclusion?
5. Is the argument valid?

Answer 1

I don't know what the symbol * means.
1) The variables are H, J and R, so there are 3 variables.
2) The number of rows is 2^3 = 8
3) Not sure without looking at the truth table.
4) Not sure without looking at the truth table.
5) The argument is valid if the very last column has all T's (true's)