Elitmus
Exam
Category
If a number x^100 have 31 digit then how many digits are there in x^1000?
Read Solution (Total 7)
-
- x^100 have 31 digits => x = 2 only as 3^100 have more than 31.
check, if
y = 2^100
=> logy = 100*log2
=> logy = 100*.301
=> logy = 30.1
=> y has 30+1= 31 digits.
so, x^1000 = 2^1000 = y
=> logy = 1000*log2
=> logy = 301
=> y has 301+1 = 302 digits.
- 10 years agoHelpfull: Yes(21) No(2)
- 10^1 has 2 digits = 10
10^2 has 3 digits = 100
10^3 has 4 digits = 1000
similarly 10^y-1 has y digits
if we have y digits in x^100 that means
10^(y-1)=x^100
10^(31-1)=x^100
taking log both side
30 log 10 = 100 log x
30 = 100 log x
now,
10^(y-1)= x^1000
y-1=1000 log x
y-1=10*100 log x
put value of 100 log x in this equation
we get y-1=10*30
y=301
Ans=301 - 10 years agoHelpfull: Yes(4) No(4)
- y=x^100 [where y is 31]
taking log both side
log y = 100 log x
log y = 100 log(0.3010) [assume the value of x]
log y = 30.1 = 31 digit [value of x = 2 ]
then
y = 2 ^ 1000
taking log both side
log y = 1000 log 2
log y = 1000*0.3010 = 301 (ans) - 10 years agoHelpfull: Yes(3) No(0)
- i think 310
- 10 years agoHelpfull: Yes(2) No(1)
- I cant understand your question can u give me option ,,,,
- 10 years agoHelpfull: Yes(1) No(0)
- @VAMI : This ans wasn't thr in the option.
- 10 years agoHelpfull: Yes(0) No(0)
- Please enter the options as well..!!
- 10 years agoHelpfull: Yes(0) No(0)
Elitmus Other Question