First you have to find out how far he ran in 12 minutes
[tex]6 \times 400 = 2400 meters[/tex]
Now we can set up a proportion to find out how long it took him to run 1000 meters or 1 kilometer
[tex] \frac{12}{2400} = \frac{x}{1000} [/tex]
We can solve to figure out that x = 5 so it took him 5 minutes to run 1 kilometer
