So - I just decided moments ago to try another telepathy test with my dad. Just one alphanumeric Pick 3 test.
For the first character, I wrote down that I thought it was an "R" or a "B". It actually turned out to be a "P". I had the right idea.
For the second character, I wrote down that I thought it was an "O" or a "Q". It really did turn out to be a "Q"! Yay!
The only thing I got right about the third character was that it was a number, I said "4" but it was actually "9".
So, all things considered, that turned out to be a pretty good one-time solo test. Cool. Thank God.