350 Senior Students - 140 Femal Senior Students = 210 Male Senior Students

140:210 is the ratio, simplified 2:3.

910 Students - 350 Senior Students = 560 Junior Students

There are the same number of junior males and junior females.

560 Junior Students /2 is now, 280 Male Junior Students and 280 Female Junior Students.

The rest should now be easy to solve.