Answer :
For this you can write the given information as a fraction and then simplify, like this
[tex]\begin{gathered} \frac{15}{30} \\ \text{Simplifying,} \\ \frac{15}{30}=\frac{15\cdot1}{15\cdot2}=\frac{1}{2}\rightarrow\text{ Because the HCF of 15 and 30 is 15} \end{gathered}[/tex]Therefore, the answer is 1 foot in 2 seconds, or, 1/2 because you don't have to enter the units.