Alexa and Siri are 21 miles apart on a trail. They start moving toward each other. Siri moves at a constant speed of 3.5 miles per hour. Alexa walks at a constant speed of 2.5 miles per hour. How long does it take until Alexa and Siri meet on the trail?

Thats where they was ported and the fields that noone really knew much about needed tended, so they put slaves out there do free work and huge profits and so on the north decided to hold its own and was more different way of survival did not have same climate conditions to afford protecting slaves from winter so expenses be diff from south