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der is a chessboard of m/n dimension......calculate no of square,reactangles & rectangles wich r not squares...in the chess board

6 Answers

1
Samarth Kashyap ·

first calcululate the total number of squares in the chess board
it is 12 + 22 + ........ + 82

now a rectangle is formed when 2 horizontal and 2 vertical lines are chosen which can be done in (nC2)*(nC2) ways (n=9 here)

but this also includes squares so subtract the no of squares from the total rectangles to get the no of rectangles which are not squares

1
Pavithra Ramamoorthy ·

mrnobody1991...

pls post a complete solution asap........

62
Lokesh Verma ·

Read these from links

[url=http://targetiit.com/iit_jee_forum/posts/number_of_rectangles_in_a_chess_board_73.html]No of Recatangles in a chessboard[/url]

and

[url=http://targetiit.com/iit_jee_forum/posts/number_of_non_congruent_rectangles_in_a_chess_boar_72.html]No of non-congruent rectangles on a hess board[/url]

1
Pavithra Ramamoorthy ·

byah.. pls check ur chatbox...

1
archana anand ·

@mrnobody19 how di u kno no. of squares in a chess board is
12+22+........+82(this is for 8/8 dimension chessboard)
it is not the normal chess board itz of m/n dimension
rest of ur answer is okay

62
Lokesh Verma ·

der is a chessboard of m/n dimension......calculate no of square,reactangles & rectangles wich r not squares...in the chess board

No of squares will be

12+22+... (m2) (if m<=n)

No of rectangles is (m+1)C2 x (n+1)C2

No of rectangles which are not squares is the difference of the second and the first number above :)

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