The total number of students in the 8th grade is 120. What is the number of girls in the grade if the number of girls is 1/3 that of boys?
Let g = girls b = boys1) b + g = 1202) g = 1/3bSubstitute 1/3b for g in 1)b + 1/3b = 1204/3b = 120/4/3. /4/3b = 120 x 3/4b = 90, g = 1/3b = 1/3(90) = 30b = 90, g = 30. ANSWER
Let b= boys, then b/3= girls,b + b/3 = 1204b/3 = 120b=120x3/4=90, girls=90/3=30