Guess My House
Logic puzzles require you to think. You will have to be logical in your reasoning.
Mac's new house number has three digits. When she challenged her friends to guess it, they tried: 135, 780, 785, and 732.
"That's amazing," Mac said. "You've each guessed exactly one digit correctly and in its right place!"
What is Mac's house number?
HintThe fact that three guesses began with a 7 will give you a good start.
Hide
Answer
182
Solution:
The first digit must be 1 or 7. It can't be 7 as only one digit is correct in each guess. So it's 1.
The other digits in guess #1 (i.e. 3 and 5) must be incorrect. Therefore, from guess #3, the second digit is 8.
Guess #4 has a correct digit which must be its third  2.
Hide
Comments
Marple
Sep 03, 2012
 Excellent! It made me think very hard! 
kidkilowatt
Sep 05, 2012
 Not extraordinarily difficult, but very engaging due to the casual, fun narrative! 
BeanSC
Sep 07, 2012
 Very well done, creative! 
dalfamnest
Sep 07, 2012
 Thanks. It's based on the old "Mastermind" logic game  which I stopped playing in early married life when my wife always beat me! It's fun to write a little storyline to go with the logic. 
ImConfused
Sep 14, 2012
 As my name goes, I'm quite confused. Do the second and third guess share the second digit? or else, what prevents the last digit from being from the 2nd guess instead of the last? 
dalfamnest
Sep 15, 2012
 Hi ImConfused! Yes, the second and third guesses both had the same digit correct. That would have to be the case, as there are only three digits and four people guessing! Hope you enjoyed it, though! 
PYTHON
Oct 03, 2012
 Cool, I liked it! 
Jeppydog
Nov 03, 2012
 GREAT PUZZLE! Elegant! And a lot of fun.
Thanks! 
HABS2933
Nov 03, 2012
 Though easy, very enjoyable. 
Jekyll
Nov 03, 2012
 How can four people each get only one digit right of a threedigit number? 
cutebug
Nov 03, 2012
 I thought it was enjoyable, although very easy. 
dalfamnest
Nov 03, 2012
 At least two of them must have guessed the same digit correctly ... which is part of the logic required to solve it! 
corcon
Nov 03, 2012
 Mind...exploding... 
FatHead
Nov 03, 2012
 Not bad, but a little too easy. I just took a random guess based on the clues, with the first possibility for the hundreds, the next possibility for the tens, and the only remaining possibility for the ones. And it checked! 
thecatladycac
Nov 03, 2012
 Fairly easy  but it is nice having a little brain stimulation, but also having the satisfaction of solving fairly quickly! I enjoyed your teaser! 
iggy39
Nov 03, 2012
 never was any good at this kind of teaser. 
auntiesis
Nov 04, 2012
 Great teaser even though it was a little on the easy side. The 3 sevens made it easy to get the first number. After that it was a piece of cake. 
trewq
Feb 21, 2013
 great job! at first, it seemed impossible, but after reading it a couple times I got it! (I did write it down though ) 
DarthXenon
Feb 26, 2013
 Here's how I found out (and it probably should be the explanation in the answer, as it may be unclear):
There are four guesses, which means that one of the digits was repeated twice.
The first digit is 1 since 7 was repeated three times, eliminating the first guess.
The second digit is 8 since it was repeated twice in the second and third guesses.
By process of elimination, 2 is the third digit, which is in the fourth guess. 
Tpopfunstar
Jul 01, 2013
 I got it right! It wasn't very difficult, but still fun 
Zykezex
Jan 05, 2014
 Great one! 
Back to Top
 
