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
