on a board having 18 rows and 16 columns, find the number of squares

options
18c2.16c2
18p2.16p2
18.16+17.15+16.14................3.1
18c2+16p2

• 
  a ractangle have m rows and n columns:
  
  the number of square is given by: m*n+(m-1)*(n-1)+(m-2)*(n-2)+.....upto 1
  
  so ans is: 18*16+17*15+16*14+.....3*1
• 9 years agoHelpfull: Yes(4) No(1)
• in these types of questions we have to visualize the grid
  now we have to find no of squares,its given by
  take side of each square as 1 unit for single square
  now total no of sqr of side 1 unit =16*18
  now total no of square of side 2 units are=take2 horizontal and 2 vertical square at start(top-left) and we can move this square15 different positions ie(16-1(this 1 unit is used for making square of side 2 units)) units horizontally simultaneously 17 units vertically down,=15*17
  similarly square of 3 units we move =14*16
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  18.16+17.15+16.14................3.1 is the answer
• 6 years agoHelpfull: Yes(0) No(0)