Question

In standard form, the number $72105.4$ is written as $7.21054\times {10}^n$ , where $n$ is equal to

• A. $2$
• B. $3$
• C. $4$
• D. $5$

Answer 1

The correct option is C

$4$

Write standard form of the given number to find the required value

Given, in standard form, the number $72105.4$ is written as $7.21054\times {10}^n$.

We know that,

Any number can be expressed as a decimal number between$1.0$ and $10.0$ ( including $1.0$ ) multiplied by a power of $10$. Such a form of a number is called its standard form or scientific notation.

Now,

$72105.4$ is written as , $7.21054\times {10}^4$

$\Rightarrow 72105.4=7.21054\times {10}^4$

Hence , $n$ is equal to $4$, so, option (C) is the correct answer.