Question
Number of cyphers after decimal before a significant figure comes in 
is
- 21
- 22
- 23
- none
Hint:
Here cypher means the number of zeroes that come before a significant number comes in a decimal figure. We need to solve the given problem using the formulas of logarithm.
The correct answer is: 22
Here, we have to find the number of cyphers.
Firstly, we have given is,
Let, A = 
Taking log both sides to base 10, we have
We have log105 = 0.6990 and log103 = 0.4770
Hence,
log10A= -100(0.699-0477)
log10A= -100(0.222)
log10A= - 22.2
We know that loga b=x so we can write, a = bx ,
A = 10-22.2
A= 1/ 1022.2
Therefore, the cypher number is 22.
The correct answer is 22.
In this question, we have to find the number of cyphers. We need to remember that the cypher number can be found from the logarithmic calculation but to find the actual value or to visualize it we need to remove the logarithm. Here, log105 = 0.6990 and log103 = 0.4770.
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is:
