There are 15 students in math class.at the begning of class everyone races into class as everyone love maths.the professor takes note of the first 5 students who gets class and ranks them according to the order in which they entred as their top 5 favourite students. in how many different ways could the professor rank their top 5 students using formulla from combinations and permutations
If the organism has no natural predators then that organism can start to overpopulate the habitat and use up valuable resources that other organisms, who DO have natural predators, need to survive and repopulate.
Ecosystems can be large and are made of biomes. Some examples of ecosystems are deserts and forests.
I believe Mechanical Force is the force you are looking for