Question

The number of significant figures in the numbers $4.8000\times {10}^4$and $48000.50$ are respectively.

• A. $5$ and $6$
• B. $5$ and $7$
• C. $2$ and $7$
• D. $2$ and $6$

Answer 1

The correct option is B

$5$ and $7$

The explanation for the correct option

1. To determine the number that is given as digits, significant figures are used. Meaningful numerical representations are carried by these digits.
2. By counting each value starting with the leftmost first non-zero digit, we may determine the number of significant digits. $12.45$ has four significant digits, for instance.
3. Each non-zero digit has importance. When a number has decimal places, the trailing zero or zeros are important. For the purpose of determining significant figures, power of $10$ is unimportant. There are $5$ major digits in $4.8000\times {10}^4$
4. So the significant digits in $4.8000\times {10}^4$ is $5$
5. Each non-zero digit has importance. No matter where the decimal point is located, all zeros that are in between two non-zero numbers are important. When a number has decimal places, the trailing zero or zeros are important. So the significant digits in $48000.50$ is $7$

Hence, option(B) i.e. $5$ and $7$ is correct