Place one of A, B, C, or D into each of the 25 empty cells in the 5x5 grid at the bottom right, so that the number of letters of each type in each column matches the number given for that type in the numbers above that column. The same for the rows: the number of letters of each type in each row will match the number given for that type in the numbers to the left of that row for the given type.
Note: Identical letters cannot be next to one another in the grid either horizontally or vertically, but may be adjacent diagonally.
++++++
A  1  1  1  1  2 
++++++
B  2  1  3  1  1 
++++++
C  1  2  1  1  0 
++++++
A B C D  1  1  0  2  2 
++++++===+===+===+===+===+
 2  1  1  1      
+++++++++++
 1  2  0  2      
+++++++++++
 1  2  1  1      
+++++++++++
 1  0  2  2      
+++++++++++
 1  3  1  0      
+++++++++++
From Mensa 365 Brain Puzzlers for 2015, by Mark Danna and Fraser Simpson, Workman Publishing, New York, puzzle for December 7.
1) Column with 3 B's
2) Row with 0 C's
3) Column with 0 C's
4) Column with 1 B
++++++
A  1  1  1  1  2 
++++++
B  2  1  3  1  1 
++++++
C  1  2  1  1  0 
++++++
A B C D  1  1  0  2  2 
++++++===+===+===+===+===+
 2  1  1  1    B   
+++++++++++
 1  2  0  2    A   
+++++++++++
 1  2  1  1  B   B   
+++++++++++
 1  0  2  2  C   C   
+++++++++++
 1  3  1  0  B   B   B 
+++++++++++
5) Two columns left with a B must go in 2nd row
6) Finish this row with 2 D's
7) Finish column 1
8) Finish row 4
9) Finish column 5
++++++
A  1  1  1  1  2 
++++++
B  2  1  3  1  1 
++++++
C  1  2  1  1  0 
++++++
A B C D  1  1  0  2  2 
++++++===+===+===+===+===+
 2  1  1  1  A   B   A 
+++++++++++
 1  2  0  2  D  B  A  B  D 
+++++++++++
 1  2  1  1  B   B   A 
+++++++++++
 1  0  2  2  C  D  C  A  D 
+++++++++++
 1  3  1  0  B   B   B 
+++++++++++
The rest goes quick ++++++
A  1  1  1  1  2 
++++++
B  2  1  3  1  1 
++++++
C  1  2  1  1  0 
++++++
A B C D  1  1  0  2  2 
++++++===+===+===+===+===+
 2  1  1  1  A  C  B  D  A 
+++++++++++
 1  2  0  2  D  B  A  B  D 
+++++++++++
 1  2  1  1  B  C  B  D  A 
+++++++++++
 1  0  2  2  C  D  C  A  D 
+++++++++++
 1  3  1  0  B  A  B  C  B 
+++++++++++

Posted by Jer
on 20151220 12:19:11 