- Study Anytime, Anywhere through Our Mobile App & Web Portal
- 1000+ Video Lectures by CAT/XAT Topper Faculties
- 400+ Hours content of CAT Preparation Videos
- 9000+ Questions in Online CAT Coaching Course
- 200+ Topic Based Tests (50+ Basic, 50+ Moderate & 50+ Advanced Level)
- 20+ CAT Mocks (Pro CATs – Best Online Tests Series for CAT)
- 10+ Mock OMETs (Online Test Series for SNAP, NMAT, IIFT, XAT, TISS, CMAT)
- Online Doubt Solving on One – to – One basis
- GD-PI-WAT Online Preparation Material
Get access to the detailed solutions to the previous years questions asked in IIFT exam
Explanation:
1 person in every 100 suffers from the disease.
Probability of a person being healthy = 99/100
In a group of 50 people if the test is positive, then he could then test each person’s blood individually otherwise he will consider that the entire group is healthy
The number of tests =50+1 = 51
The probability that all the people in the group are healthy = 50C50 x (99/100)50
= approx 0.605
So the probability that at-least one person suffers in a group of 50 = 1-0.605= 0.395
Expected number of tests = 51*0.395 + 0.605*1
= 20.145+0.605
=20.75 = 21 tests.
C is the correct answer.