In a certain examination paper, there are n questions. For j=1,2....n there are 2^(n-1) students with answer j or more questions wrongly. If total number of wrong answers is 4095 then the value of n is.......?

• Let us say there are only 3 questions. Thus there are 2^(3-1)=4 students who have done 1 or more questions wrongly, 2^(3-2)=2 students who have done 2 or more questions wrongly, 2^(3-3)=1 student who had done all three questions wrongly.
  Total no. of wrong answer=4+2+1=7=2^3 -1=2^n -1
  
  In our question, Total no. of wrong answer=4095=2^12 -1
  then n=12.
  Answer, total no. of questions=12
• 9 years agoHelpfull: Yes(13) No(0)
• 2^(n)-1=4095
  2^n=4096
  2^n=2^12
  therefore n=12
  
• 9 years agoHelpfull: Yes(5) No(4)
• ans is 11 i think .....
• 9 years agoHelpfull: Yes(0) No(1)
• n=12
  I think 2^(n)-1
• 9 years agoHelpfull: Yes(0) No(1)
• 2^(n-1)=4095
  2^n=4096
  so n=12
• 9 years agoHelpfull: Yes(0) No(0)