I WILL MARK BRANLIEST IF THIS IS ANSWERED WITHIN 10 MINUTES
For a standard normal distribution, which of the following expressions must always be equal to 1?
A. P (z less-than-or-equal-to a) - P (negative a less-than-or-equal-to z less-than-or-equal-to z) - P (z greater-than-or-equal-to a)
B. P (z less-than-or-equal-to a) - P (negative a less-than-or-equal-to z less-than-or-equal-to z) + P (z greater-than-or-equal-to a)
C. P (z less-than-or-equal-to a) + P (negative a less-than-or-equal-to z less-than-or-equal-to z) minus P (z greater-than-or-equal-to a)
D. P (z less-than-or-equal-to a) + P (negative a less-than-or-equal-to z less-than-or-equal-to z) + P (z greater-than-or-equal-to a)

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

Will give brainliest immeadeately true or false: the origin woud be included in the solution set for the inequality: y< 2x-5

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2