What Four Numbers?
Math brain teasers require computations to solve.
Using the clues below, what four numbers am I thinking of?
The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.
Answer
The digits are 12, 5, 6, and 8.
Hide
Comments
Zag24
Jan 21, 2012
 By this sentence: "If you subtract the middle two numbers, it equals two." Are you trying to say "the difference between the two middle numbers is two" ? I'm pretty sure that's what you meant, but that's not what your sentence actually means. 
JasonD
Jan 31, 2012
 A fun riddle, but two minor nitpicks:
I wouldn't call them "digits" in the answer.
One could argue for a solution of 4,7,9,11 unless the conditions say "exactly one odd number". 
Rhythmic
Feb 03, 2012
 I got 4, 7, 9, and 11 for the same reason. 
olderekg
Feb 08, 2012
 The digits are 12, 5, 6, and 8. 
Nsengi
Sep 20, 2012
 your answer is not true because you say that the difference of two middle number is equal to two but for your answer the difference is equal to one. 
RRAMMOHAN
Oct 07, 2012
 If you write the answer (the same 4 numbers given by the author) in the order 12, 8, 6 and 5, then the doubts would be cleared. I got these 4 nos. in this order in my solution.
(Yes, it would have helped if the problem had mentioned 'the other two numbers' (meaning thereby other than the highest and lowest numbers) instead of 'the middle two numbers'.) 
Back to Top
 
