a group of 16 people is choosing a chairperson and vice chairperson They put all 16 peoples name into a hat the first name drawn becomes chair second name becomes vice chair How many possible combinations of chair and vice chair are there?​

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Aclassroom is made up of 11 boys and 14 girls. the teacher has four main classroom responsibilities that she wants to hand out to four different students (one for each of the four students). if the teacher chooses 4 of the students at random, then what is the probability that the four students chosen to complete the responsibilities will be all boys?