A metal plate is located in the xy-plane such that the temperature T at point (x,y) is inversely proportional to the distance from the origin and the temperature at the point P(3,4) is 100*F. (Assume distance in meters). Find the average temperature:

a/ Over a circular disk centered at the origin of radius 10 m.

b/ Over the region = {(x,y) R²: 0 <= x <= 10 0 <= y <= x}.