We have a rectangular sheet with length (l) and width (w)
It is also given that length is four times the width,
![\begin{gathered} l=4w \\ w=(l)/(4) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/slhvkti03b7d7bnavewchxi1530k6aspjj.png)
The perimeter of the sheet must be less than 100 inches,
![p<100\:](https://img.qammunity.org/2023/formulas/mathematics/college/2ucdnmy6b5k99i55d4vcxhy81sr2s0e6ru.png)
Recall that the perimeter of a rectangular shape is given by
![p=2(l+w)](https://img.qammunity.org/2023/formulas/mathematics/middle-school/wf5n5ypm36dvt44k1uaarhd9t4ggu6blwc.png)
Substitute it into the above inequality
![2(l+w)<100_{}](https://img.qammunity.org/2023/formulas/mathematics/college/8zz93c15h6i1iihio1qz8350oks6f7snr3.png)
Now substitute the value of w into the above inequality.
![2(l+(l)/(4))<100](https://img.qammunity.org/2023/formulas/mathematics/college/81zcbap9h9xnk0uzzwi71ee0tr7zvulbtb.png)
Now let us simplify the above inequality
![\begin{gathered} 2(l+(l)/(4))<100 \\ 2((4l+l)/(4))<100 \\ 2((5l)/(4))<100 \\ (5l)/(2)<100 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/j2vxz0ggkykkwx4akh7iu1yfjuygxnfdhx.png)
Therefore, the possible lengths of the rectangular sheet are given by the inequality
![(5l)/(2)<100](https://img.qammunity.org/2023/formulas/mathematics/college/a3j67fl45kw4tst85asus18ye688cohhkl.png)
The 2nd option is the correct answer.