a bag contains 6 purple sticks, 2 orange sticks, and 4 black sticks and you ask a friend to pick one without looking what is the probability that the stick will be purple. who knows this question? lol it's confusing to me

What is the missing constant term in the perfect square that starts with x^2 -20x

How many solutions does the nonlinear system of equations graphed bellow have?

Anew test for ra is being developed. the test is administered to 750 patients with ra and 750 without ra. for the sake of the question, assume the prevalence of ra in this population is 50%. of the 750 patients with ra, 575 have a positive result. of the 750 patients without ra, 150 have a positive result. what is the positive predictive value of the new test? a575/(575+150) b. 600/(600+ 150) c. 575/(575+125) d. 600/(600+ 125)