Two bags contain coloured cubes. Bag 1 has 2 green cubes and 1 yellow. Bag 2 has 3 green cubes and 1 yellow. Determine each probability if you choose 2 cubes from Bag 1 without returning the first cube and 1 cube from bag 2. Use a visual model to explain your thinking. a) All three cubes are the same colour
b) Exactly 2 cubes are the same colour
c) All three cubes are different colours

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)