Mary leaves her house to take a walk. the graph shows the distance, d, in feet from her house that mary is at any given time, t, in minutes. how many minutes has mary walked when she reaches the farthest point from her house

You haven't provided the graph, therefore, I cannot provide you with a specific solution for this question.
However, I will tell you how to solve it and you can apply on the graph you have.

Now, we are given that:
x-axis represents the distance in ft
y-axis represents the time in minutes

To get the time that she has walked when she reaches the farthest point from her house, all you have to do is:
1- go to the greatest point on the x-axis. This point would be representing the farthest distance.
2- get the value of the y corresponding to the x-point you got in step one. This would be the time walked when she reaches the farthest point which is the value you are looking for.

Hope this helps :)