Answer
\[4.0625\times {{10}^{4}}\,\text{years}\]
Work Step by Step
The number of years in \[1.3\,\,\text{trillion}\] seconds is calculated as follows:
\[\begin{align}
& 1\,\text{year}=3.2\times {{10}^{7}}\sec \\
& 1sec=\frac{1}{3.2\times {{10}^{7}}}\,\text{years} \\
& 1.3\times {{10}^{12}}\sec =\frac{1}{3.2\times {{10}^{7}}}\times 1.3\times {{10}^{12}}\,\text{years} \\
& =4.0625\times {{10}^{4}}\,\text{years}
\end{align}\]
The given number in scientific notation is \[4.0625\times {{10}^{4}}\,\text{years}\]
