Someone please help me with this, thank you!!

Hurry if the population of of an ant hill doubles every 10 days and there are currently 100 ants living in the ant hill what will the ant population be in 20 days

In a small section of a stadium there are 40 spectators watching a game between the cook islands and fiji. they all support at least one of the two teams. 25 spectators support the cook islands and 16 of these support both teams. how many support only fiji?

An incoming airplane is x miles due north from the control tower at an airport. a second incoming airplane is y miles due east of the same control tower. the shortest distance between the two airplanes is z miles. which of the following functions would best model the situation above?