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Arithmetic
In a certain examination papers there are n questions,for j=1,2,...n there are
2^n-1 studentswho answered j or more questions wrongly..if the total no of wrong answers is 4095,then the value of n is:
Read Solution (Total 7)
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- 2^n-1=4095
2^n=4096
2^n=2^12
n=12 - 10 years agoHelpfull: Yes(22) No(1)
- =>2^n - 1 =4095
=>2^n=4096 or 2^12
n=12 - 10 years agoHelpfull: Yes(1) No(1)
- answer is 11
since 2^n-1 - 10 years agoHelpfull: Yes(1) No(1)
- Make a correction-,'2^(n-j) students answered j questions wrongly'.
Number of wrong answers=2^(n-1)+2^(n-2)+ ...+2^(n-(n-1))+2^(n-n)=2^n-1.
Therefore, 2^n-1=4095 => n=12. - 10 years agoHelpfull: Yes(1) No(0)
- 2^N-1=4095;
2^N=4095+1=4096
2^12=4096
SO ANS IS:12 - 10 years agoHelpfull: Yes(1) No(0)
- 4096=2^12
4096-1=4095
so n=12 - 10 years agoHelpfull: Yes(0) No(0)
- 2^N-1=4095;
2^N=4095+1=4096
2^16=4096
SO ANS IS:16 - 10 years agoHelpfull: Yes(0) No(10)
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