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?

Correct Option: (b) 40%

Let the total number of students in the class be 100. Then, number of Indian students = 60 (60%), and number of foreign students = 40 (40%). Total number of girls = 50 (50% of 100). Number of Indian girls = 30% of Indian students = 30% of 60 = 0.30 × 60 = 18. Since total girls = 50, the number of foreign girls = Total girls - Indian girls = 50 - 18 = 32. Total foreign students = 40. Therefore, the number of foreign boys = Total foreign students - Foreign girls = 40 - 32 = 8. We need to find the percentage of foreign students who are boys: (Foreign boys / Total foreign students) × 100 = (8 / 40) × 100 = 0.20 × 100 = 20%. Wait, let's re-read carefully: 'what percentage of foreign students are boys?' -> wait, 8 out of 40 is 20%. Let's check options: (a) 45%, (b) 40%, (c) 30%, (d) 20%. Option (d) corresponds to 20%, which is index 3. Let's double check: Total students = 100. Indians = 60 (Boys = 42, Girls = 18). Foreigners = 40 (Girls = 32, Boys = 8). Percentage of foreign boys among foreign students = 8 / 40 = 20%. Thus, option (d) is correct, index 3.