There are 4 students in a line, two 9th Graders and two 10th graders. Each grade has 1 boy and 1 girl. 1 and 2 represent the 9th Graders where 1 is the boy and 2 is the girl. 3 and 4 represent the 10th Graders where 3 is the boy and 4 is the girl. The following were observed :
- There is a boy at the leftmost of the line
- Two 10th Graders are not next to each other
- Two Girls are next to each other
- 4 is at the rightmost of the line
- If 1 is the leftmost then 3 is not in front or at the back of 2
Find the arrangement of the students from lest to right.