Help please, help me

What situation is an example of an observational study

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

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply