This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Predictive value of a positive test is defined as ? 
Select and explain. 
A. True + ve/true + ye + false - ye x 1 00, B. True + ye/true + ye + false + ye x 100, C. False + ve/true + ve + false + vex 100, D. False + ve/true + ve + false - vex 100
B: True + ye/true + ye + false + ye x 100
Answer: B: True + ye/true + ye + false + ye x 100 
Explanation: Ans. is `b' i.e., True + ye (true + ye + false + ye) x 100