Elitmus
Exam
Numerical Ability
Number System
If x^100 is 31 digit number then x^1000 contains how many digits.
Read Solution (Total 5)
-
- no=x^31
no of digits in any no =floor[log(n)]+1
so 100logx+1=31
100logx=30
hence
1000logx+1=300+1=301
so answer is 301
- 9 years agoHelpfull: Yes(26) No(12)
- 10^1 has 2 digits = 10
10^2 has 3 digits = 100
10^3 has 4 digits = 1000
10^30 has 31 digits
therefore, 10^30=x^100
30=100 log x
multiplaying both side by 10
30*10=10*100 log x
300= 1000 log x = 300+1=301
so 301 is correct answer - 9 years agoHelpfull: Yes(15) No(5)
- ans is 302
log 2 x 1000=301.029995664
choose higher natural no - 9 years agoHelpfull: Yes(3) No(0)
- x^100 have 31 digits => x = 2 only as 3^100 have more than 31. but for x=2 no of digit will be 30
so, x^1000 = 2^1000 = y
=> logy = 1000*log2=1000*0.301
=> logy = 301
so y has 301+1 = 302 digits. - 9 years agoHelpfull: Yes(2) No(0)
- if number is 2 digit it is 10 if number is 3 digit 10^2............if x digit then 10^(x-1)
10^(x-1)=x^100 take log both side (x-1)=100 logx
x-1=31
logx=0.31
similarly10^(a-1)= x^1000
take log both side
a-1=1000 logx
put the value of logx
a=311 - 9 years agoHelpfull: Yes(1) No(12)
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