Question

100 students of a class are picked randomly and instructed to make a human chain such that every prime number positition and perfect square positions are occupied by girls only and the rest are occupied by boys only. The ratio of the girls in the first 50 students to that of the number of girls in the next 50 students is??

Answer 1

 the prime numbers between 1-50 are:
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47=15 in number
while perfect squares between 1-50 are;
1,4,9,16,25,36,49=7 in numbers
Hence,the total sum of girls=7+15=22 girls
Prime numbers between 51-100;
53,59,61,67,71,73,79,83,89,97=10
perfect squares between 51-100 are;
64,81,100=3 
total number of girls from 51-100=10+3=13
which is 22/13
 hence the ratio =22:13