At forrest elementary (k-5) 5/12 of the students are fourth and fifth graders. there are 300 more k-3 students than fourth and fifth graders. a. how many total students are at the school. b. of the fourth graders and fifth graders 2/5 are fourth graders. how many fifth graders are there.

Let the number of 4th and 5th graders be x.
The  number of k-3 graders will be (x+300)
The fraction of 4th and 5th graders is 5/12
The fraction of the whole students combined is 1/1
The fraction of k-3 graders is 1-5/12=7/12
The total number of students will be x+(x+300)=2x+300
the fraction of 4th and 5th graders will be given by:
x/(2x+300)=5/12
12x=5(2x+300)
12x=10x+1500
2x=1500
x=1500/2=750
Thus the total number of students will be:
2x+300
=2*750+300
=1500+300
=1800

b] Given that of the 4th and 5th graders, (x=750), 2/5 are 4th graders, therefore the fraction of 5th graders will be:
1-2/5=3/5
the total number of 5th graders will be:
3/5*750
=450
The number of 5th graders will be 450