Here are two methods to make a 4-digit code. Codes can have repeated digits. Method A for the first two digits use an even number between 29 and 100, for the last two digits use a multiple of 11. Method B use 4 digits in the order odd even odd even, do not use the digit zero. How many more codes can be made with method B than with method A?

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)