Can someone plz me with this math problem.

The circumference of a circle is 5 pi cm. what is the area of the circle?

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?