What are the exact total miles in a 5k race and a 10k race?

convert by multiplying by one.
5 km =
5 km *39.37 inches/1 meter*1 foot/12 inches*1 mi/5280 feet*1000meter/km=
3.10685 miles
multiply by two for 10k.

there are 39.37 inches in a meter. It should be fairly easy from there if we can keep track of the units.
We have (39.37 in)/(1 meter) = x/5,000 meters and we multiply the means and the extremes and set them = to each other. So we get x = (39.37(5000)/1) inches (the meters cancel)
x = 196,850 inches
Now we divide 196,850 by something to change it to feet and we divide that number by something to change the feet to miles. If our answer comes out as a repeating decimal we put a bar over the numbers that repeat and we then have an exact answer for the number of miles in 5K. You are on your own (except for many others present to help) now because I need to leave.