Hi all, I need some help regarding these practice problems for AP Microeconomics. I just haven't been able to grasp how to do these types of problem sets, but I already answered the other 7; I just haven't been able to answer these last 3. So any help would be greatly appreciated!

What will happen to a firms profit maximizing quantity in the short run if there is a significant increase in rent

Afootball game between the thunder and the sharks is in its closing minutes, with the thunder ahead by 20 points. the thunder’s coach considers sending in the second-string quarterback. this would reduce the risk of the star quarterback getting injured, but the second-string quarterback is not very good. complete the passage describing the coach’s decision in economic terms.

Which best explains why the number of states in the world increased significantly between 1985 and 1995? the map of southeast asia was redrawn, and new countries were formed. new states were formed when the soviet union collapsed. many african states received independence from their colonizers. communist countries seeking to spread their influence created new satellite states. civil wars in central america fueled the creation of new states.