Tonya runs 8 kilometers in 60 minutes. At this rate, how long it take her to run 2 kilometers

15 Minutes

You have 8 km in an hour.

Divide all that by two and you'll have 4 km in 30 mins.

Then divide by two again to end up with 2 km in 15 mins.

You could alternatively divide by four from the beginning, but I find this easier.