Let's play mini-Sudoku!

We wish to place an "X" in four boxes, such that there is exactly one "X" in each row, column, and 2x2 outlined box. For example:

In how many ways can we do this?

Please explain very well in this quesiton.

Guest Mar 18, 2015

#1**+10 **

I think this is it

1) there are 4 choices for the first row, the X can go anywhere. Just put your X in

2) There are only 2 choices for the next row because it cannot go in the same box as the first one did.

3) There are 2 choices for the next row because it can go in either box but it cannot go under either of the 2 x's that are already there.

4) There is only one possibility left for the last row

so the number of possibilities is 4*2*2*1=16

Melody
Mar 19, 2015

#1**+10 **

Best Answer

I think this is it

1) there are 4 choices for the first row, the X can go anywhere. Just put your X in

2) There are only 2 choices for the next row because it cannot go in the same box as the first one did.

3) There are 2 choices for the next row because it can go in either box but it cannot go under either of the 2 x's that are already there.

4) There is only one possibility left for the last row

so the number of possibilities is 4*2*2*1=16

Melody
Mar 19, 2015