Total number of students in different subjects of a college and percentage of girls and boys are shown in the below table.
| Subjects | Number of Students | Girls % | Boys % |
| Mathematics | 840 | 40 | 60 |
| Chemistry | 220 | 70 | 30 |
| Physics | 450 | 30 | 70 |
| Biology | 200 | 80 | 20 |
What is the ratio of girl students of Mathematics and Chemistry to the number of boy students of Physics and Biology?