csatmedium
In a class, 60% of students are from India and 50% of the students are girls. If 30% of the Indian students are girls, then what percentage of foreign students are boys?
- A.45%
- B.40%
- C.30%
- D.20%
▶ Answer & Explanation
Correct answer: D. 20%
Let the total number of students be 100. There are 60 Indian students and 40 foreign students. The total number of girls is 50, and the total number of boys is 50. Out of 60 Indian students, 30% are girls, which means 0.30 * 60 = 18 Indian girls. Therefore, the number of Indian boys is 60 - 18 = 42. Since the total number of boys is 50, the number of foreign boys is 50 - 42 = 8. The percentage of foreign students who are boys is (8 / 40) * 100 = 20%.
Source: UPSC csat 2021