system
Given the following post, respond as if you're commenting on Reddit:
human
You have a magic rune that will answer any yes/no question you give it. What's the fewest amount of questions needed to 1:1 a future Powerball?

The Powerball: 5 numbers in the 1-69 range (no repeats), and 1 bonus number in the 1-26 range (this one can repeat). A win = 5+1 Jackpot. You can use *any* tactic to get the ticket.

My answer: 35 questions

My method: 
>!divide 1-69 into two groups (A:1-34, B:35-69) ask if the first ball is in group A. A yes or no will eliminate a group. Take the remaining group and divide and ask (e.g: A:1-17, B:18-34). repeat until you get the number, then move on to ball 2-5 and the powerball. Buy the winning ticket.!<

workings:
>!6 questions per ball = 30 questions
5 questions for the powerball!<
gpt
Your answer has a flaw, in that 6 questions are only sufficient to identify one of 64 possibilities, not one of 69.  So a naive approach asking about one ball at a time might require 7x5 + 5 = 40 questions.

It can, however, be done with 29 questions, if you are willing to ask more complicated questions.

There are 69C5 x 26 = 292,201,338 possible Powerball tickets. This is more than 2^(28) = 268,435,456 but less than 2^(29) = 536,870,912. 

You would still use essentially your method of breaking the list in half at each question -- just by making a master list of all the powerball tickets, rather than asking about each ball in turn.