Allison ran 3/8 km (0.375 km) in 3 minutes.
Set up a proportion to find how long it takes for her to run 1 km
[tex]\frac{0.375\textrm{km}}{3 \textrm{min}} = \frac{1\textrm{km}}{x \textrm{min}}[/tex]
Cross multiply to get:
[tex]3 = 0.375x[/tex]
Solve:
[tex]x = \frac{3}{0.375}[/tex]
x = 8 minutes