Riddle: I had $13.00. My mom gave me $10.00 while my dad gave me $30.00. My aunt and uncle gave me $100.00. I had another $7.00. How much did I have?
The money you had is 10 dollars. That is before your parents and relatives gave you additional money.
However, given that the logic and time of the tense is in the past, it is safe to assume that the question pertains to the money you had originally before you received external money from someone else.
Therefore, you had 13 dollars and another 7 dollars originally with you, which sums up to 20 dollars.
The answer to the I Had 13.00 riddle is 20 dollars.