how many parallelograms are formed by a set of 4parallel lines intersecting an other set of 7 parallel lines

• Let there be 4 horizontal set of parallel lines and 7 vertical set of parallel line.(U can also consider vice-versa)
  Now for a parallelogram, u need 2 horizontally parallel and 2 vertically parallel lines ie. we need to choose 2 lines from each set.
  So the solution will be 7C2*4C2=126
• 11 years agoHelpfull: Yes(53) No(1)
• 4C2 * 7C2 = 6*21= 126 parallelograms
• 11 years agoHelpfull: Yes(11) No(4)
• since as we know that in a parallelogram,we need 2 horizontally parallel lines and 2 vertically parallel lines ie. we need to choose 2 lines from each set.so we get 7c2*4c2=21*6=126....so we get 126 parallelograms
• 11 years agoHelpfull: Yes(7) No(2)
• ((36+6)*(9+3))/4=126 parallalogram
• 11 years agoHelpfull: Yes(5) No(2)
• for a parallelogram 4 lines are req..
  thus
  4C2*7C2=126
• 11 years agoHelpfull: Yes(3) No(0)
• it should be 30240
• 11 years agoHelpfull: Yes(1) No(25)
• (7c2)(4c2)=126
• 8 years agoHelpfull: Yes(0) No(0)
• 7c2*4c2=126
  
• 8 years agoHelpfull: Yes(0) No(0)
• 126 PARALLELOGRAMS..
  EXPLANATION:- 2 PARALLEL HORIZANTAL LINES AND 2 VERTICAL(LITTLE GRADIENT)LINES FORMS A PARALLELOGRAM,,
  SO 2C2*2C2= 1 PARALLELOGRAM....
  SIMILARLY, 4C2*7C2=126 PARALLELOGRAMS..
• 8 years agoHelpfull: Yes(0) No(0)
• 4c2*7c2=126
• 8 years agoHelpfull: Yes(0) No(0)
• (5c2)*7c2 parallelogram means two lines must be parallel so pair them and we have 2 sets one intersecting with the other ,the total combinations can be known using this formula
• 8 years agoHelpfull: Yes(0) No(0)
• 18
  construct 4 parallel lines and 7 other lines intersecting those 4 lines.
• 7 years agoHelpfull: Yes(0) No(0)
• 4C2*7C2=126
• 7 years agoHelpfull: Yes(0) No(0)
• 4C2 X 7C2 = 126 ans........
• 7 years agoHelpfull: Yes(0) No(0)
• 7C2*4C2=126
• 6 years agoHelpfull: Yes(0) No(0)