To find the unit rate, you have to divide 6 lawns and 3 hours by three to find how many lawns they can cut per hour, because then, with the unit rate, you can find how many lawns they can cut in any amount of time. 6 divided by 3 is 2, and 3 divided by 3 is one, so Brodie and Cindy's rate per hour for cutting lawns is 2 lawns per hour.