Your company is hosting a benefit 5 kilometer race.
how long will the race be to the nearest tenth of a mile?

In this question the main part is to convert the kilometer to miles and then writing the answer to the nearest tenth of a mile. the information given in the question is that the race is for a distance of 5 kilometers.
Now we already know
1 km = 0.6214 mile
Then
5 km = ( 0.6214 * 5) miles
         = 3.107 miles
         = 3.11 miles
So the actual distance when converted to miles will be 3.11 miles. I hope this is the answer you were looking for. This is the simplest way for doing such problems and in future you can follow this method to find the answers without the need of any help.

5 Kilometers is 3.10686 Miles
3.1 Miles to the nearest tenth of a mile.

Iknow one of the answers is a and maybe b but not 100% sure about b