We have square of side length 5cm. Find the perimeter of 9th square formed by joining the mid points of each previous square?
(a)5/4 (b)5/4rt2 (c)5/8 (d)5/16

• Here one formula is there X/sqrt(2^(n-1)
  here x=5 ,n=9 then 5/sqrt(2^8)
  =>5/16
  find out the perimeter of the square is 4*5/16=5/4
  option a is correct
• 9 years agoHelpfull: Yes(16) No(2)
• perimeter of 1st square formed by joining midpoint=20/rt2
  
  perimeter of 2nd square formed by joining midpoints=20/2
  
  so it forms GP WITH common ratio=1/rt2
  
  its nth term =20/((rt2)^n), so put n=9 we get (b) as the answer
  
• 9 years agoHelpfull: Yes(11) No(6)
• 5/4
  side/sqrt2^(n-1)=5/sqrt2^(9-1)=5/4
• 9 years agoHelpfull: Yes(4) No(4)
• option a is answer
• 9 years agoHelpfull: Yes(3) No(2)
• a) will be the ri8 ans.
  
• 9 years agoHelpfull: Yes(3) No(3)
• b is right
• 9 years agoHelpfull: Yes(2) No(2)
• it is given in the question that boys are one more than girl.
  it means in the total(21) 11 are boys and 10 are girls.
  total no of ways=(10*11!/3!8!)+(11*10!/3!7!)=1650+1320=2970.
• 9 years agoHelpfull: Yes(2) No(2)
• option (c) is correct
• 9 years agoHelpfull: Yes(1) No(5)
• (b) is correct
• 9 years agoHelpfull: Yes(1) No(1)
• vai explain it in correct manner
  how will i get the four sqre joiming whose mid pnts we will get the sqre?
  
• 9 years agoHelpfull: Yes(1) No(0)
• formula: side/sqr root(2^n-1) where n is d no. of squares formed. Substituting in d formula we get 5/16. Option D.
• 9 years agoHelpfull: Yes(1) No(0)
• plz provide a detailed soln
  
• 9 years agoHelpfull: Yes(0) No(0)
• perimeter form a G.P : 20, 10rt2 ,...........so on
  so, r= (10rt2)/20 = {1/(rt2)}
  9th term i.e perimeter of 9th square = a*r^(n-1)= 20* {(1/(rt2))^8}= 5/4
• 9 years agoHelpfull: Yes(0) No(0)