Bob Knights Liver said:
I got it in 2.
12+35=47
6+6+7=19
My stats out of 18 games played are:
Two guesses: 5
Three guesses: 3
Four guesses: 7
F ive guesses: 3
How does your second guess make any sense with your first guess? That is a strange guess, especially if the goal is to find out as much information as possible. But you may have a different approach than me.
Your starting line is good and gives good information... It establishes that you are dealing with a # sign # sign # = # # setup. Additionally, your number pool is down to 1, 6, 7, 8, 9, 0.
But why would you double your 6 in your second guess? If you are wrong (which you would be 95% of the time), you have set yourself up for a non-optimal third guess (because you still don't know if an 8 or 0 will be in the equation).
The same question goes even moreso for the double + sign (you may find the spot where the + goes, but if the equation isn't double +, you aren't finding any new information).
Working from the standpoint and information provided from your first guess, there are several much better guesses on your second try that will provide more information for your third try:
9 + 7 - 6 = 1 0
9 + 8 - 7 = 1 0
9 + 7 + 0 = 1 6
9 + 7 - 0 = 1 6
In any of these 4 tries, you are getting information on an extra number and, for 3 of the tries, you are figuring out if there is a - in the equation. And, if you don't have communative answers turned on, you have even more combinations of guesses you could make for your second try (by mixing up the order of numbers).
Even guesses like:
7 / 1 + 9 = 1 6
9 * 7 + 8 = 7 1
7 * 1 + 9 = 1 6
Would be better than your second guess because, even though you are duplicating a #, there is statistically a much better chance to have double 7 or double 1 then there is to have double 6 (or double 8, 9 or 0) because you already know there is at least one 7 and one 1 in the equation (based on your first guess).
Im curious if your thinking may go a level deeper than mine and I'm missing something?
I like math and so I might have overthought this just a bit.