Question

Which of the following numbers is less than zero?

$$\begin{gathered} \mathbf{A}\mathbf{1}\mathbf{.}\mathbf{03}\times {\mathbf{10}}^{-\mathbf{21}} \\ \mathbf{G}\mathbf{7}\mathbf{.}\mathbf{5}\mathbf{\times }{\mathbf{10}}^2 \\ \mathbf{H}\mathbf{8}\mathbf{.}\mathbf{21543}\mathbf{\times }{\mathbf{10}}^{10} \\ \mathbf{J}\mathbf{none}\mathbf{}\mathbf{of}\mathbf{}\mathbf{the}\mathbf{}\mathbf{above} \end{gathered}$$

Short answer

None of the above number is less than zero.

Step-by-step solution

Step 1. Check.

Check whether$1.03\times {10}^{-21}$ is less than zero or not.

$1.03\times {10}^{-21}$can be written as $1.03\times \frac{1}{{10}^{21}}$. This number is smaller in quantity but not less than zero.

Step 2. Check.

Check whether$7.5\times {10}^2$ is less than zero or not.

$7.5\times {10}^2$can be written in standard form as 750. Therefore, this number is greater than zero.

Step 3. Check.

Check whether$8.21543\times {10}^{10}$ is less than zero or not.

$8.21543\times {10}^{10}$is very big quantity therefore, it is greater than zero.

Step 4. Write the conclusion.

As all the three numbers are greater than zero, option J is the required answer.