+0  
 
0
36
1
avatar

The 5*5 grid shown contains a collection of squares with sizes from 1*1 to 5*5. How many of these squares contain the black square?

 

 Dec 15, 2021
 #1
avatar
+1

1*1 squares: only 1

2*2 squares: the black square could either go top left, top right, bottom left, or bottom right, so 4

3*3 squares: also 4, since 5 of the squares would go off-screen

4*4 squares: there is only a total of 4 4*4 squares in the 5*5 square, and all 4 of them contains the black square

5*5 square: only 1 and contains all the squares

1 + 4 + 4 + 4 + 1 = 14

 Dec 16, 2021

11 Online Users