José rode his trail bike for 10 miles. Two-thirds of the distance was over
A mountain trail. How long is the mountain trail? All I need to know is what property to use Im so confused.

We don't do your homework for you.
What is your answer?
https://www.askmehelpdesk.com/other-subjects/announcement-u-b-read-first-expectations-homework-help-board-b-u.html

I just need to know what property to use add, subtract, multiply, or divide?

What property? How about the 'common sense' property. What's two-thirds of 10?

I think José needs to ride his bike to your house and kick some common sense into you.

2/3/10

2/3 x 10/1 = your answer