The GATE Grind

GATE 2016 EC – Question 6

General Aptitude · Quantitative Aptitude: Probability and Combinatorics · 2 marks · Multiple choice

A person moving through a tuberculosis prone zone has a 50% probability of becoming infected. However, only 30% of infected people develop the disease. What percentage of people moving through a tuberculosis prone zone remains infected but does not show symptoms of disease?

  1. 15
  2. 33
  3. 35
  4. 37

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (C) 35

Explanation

Half the people are infected. Of those, 30% develop the disease, so 70% remain infected without symptoms. That is $0.5 \times 0.7 = 0.35$, or 35 percent of all people.