How to solve this problem that don't nor know

There are 12 boy and13 girls in a class. if the teacher randomly chooses a student’s name out of a hat what is the probability it will be a girl

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

Ineed with angles and the measure of them i have abc a is 65 and b is (3x-10) and c is (2x) find the value of x