A line segment can be drawn from each vertex of a polygon to every other vertex, forming the sides and diagonals of the polygon. A square, for example, has 4 sides and 2 diagonals. Using combinations, write an expression that would give you the total number of sides and diagonals for a polygon with n sides.

Consider a bag that contains 220 coins of which 6 are rare indian pennies. for the given pair of events a and b, complete parts (a) and (b) below. a: when one of the 220 coins is randomly selected, it is one of the 6 indian pennies. b: when another one of the 220 coins is randomly selected (with replacement), it is also one of the 6 indian pennies. a. determine whether events a and b are independent or dependent. b. find p(a and b), the probability that events a and b both occur.