the consecutive numbers are removed from thr progression 1,2,3,....,n the arithmetic mean of the remaining number is 261/4 the value of n is

• We know that ,
  sum of natural number or consecutive = n*(n+1)/2
  And the mean of this consecutive no is
  = (n*(n+1)/2)/n
  = (n*(n+1)/(2*n))
  = (n+1)/2
  Therefore,
  (n+1)/2 = 261/4
  (n+1)= 261/2
  So, n = (261/2-1)=129.5
  which near equals to 130
• 9 years agoHelpfull: Yes(9) No(25)
• any two consecutive numbers you eliminate,but the average always must be in the range from (n+1/2)+1 to (n+1/2)-1
  here the average after removing consecutive nos is 26.25
  now we have to check options.say the option is given 50.
  then,average of (1+2+....+50)50=51/2=25.5
  it covers the range 24.5 to 26.5
  so 26.25 belongs to that range.so ans=50
  
• 9 years agoHelpfull: Yes(8) No(0)
• mean of remaining numbers is 26 1/4 and not 261/4.....kindly change ur ans sumanta
• 9 years agoHelpfull: Yes(6) No(1)
• but the condition given is that 2 consecutive numbers are removed.so this z not the exact correct answer ryt
  
  
• 9 years agoHelpfull: Yes(4) No(2)
• mean of n-2 numbers (i.e.,after removing two consecutive numbers from n natural numbers) is=n/2(2*a+(n-1)*d)/n
  here n=n-2
  ((n-2)/2)((2+n-2-1)*1)/(n-2)=105/4
  after solving n=53.5
  
• 9 years agoHelpfull: Yes(4) No(2)