The variable expression 8=n

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.

Math i have no idea how to do a and b

Kari plans to sample 20 people of a population that contains 100 students. she wants to determine how many people wake up before 6 a.m. which sample is the most random?