Your teacher divides the class into groups of 5 for an activity. how many possibilities are there for the group that contains you if there are 25 students in the class in all？（hint：how many remain to be chosen）

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters