Hi can someone me? if sin2a=cos 3a find the value of a. can you explain in full detail how you arrived at your answer? also find the exact value of (sec30)^2. will i need to use a calculator in order to solve this prob?

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