How do you calculate the average mark?

43lbs of tomatos cost $387. how much would 41lbs cost

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

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?