From the 3 options listed, both [tex]5.25[/tex] in and [tex]6.5[/tex] in could be measures found using a ruler with eighth inches marked, because those decimals can be written in terms of eighth fractions.
[tex]5.25 $in $ \rightarrow (5 + 0.25) $in $ \rightarrow (5 + \frac{2}{8} ) $in$ \\
6.5 $in $ \rightarrow (6 + 0.5) $in $ \rightarrow (5 + \frac{4}{8} ) $in$[/tex]
The other option, [tex]7.1[/tex] in, is not a possibility because 0.1 cannot be written as a fraction of 8 that is marked on the ruler.
