Can a prime number be a multiple of any other number except itself

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

If the value of cos330°is√3/2 then find cos 165°.

Which expression is the factorization of x^2+10+21