The ratio of girls to boys in mr. smith's homeroom is 3: 4. the ratio in mr. smith's homeroom to students in the whole 7th grade is 1: 5. the ratio of students in 7th grade to students in the whole middle school is 2: 7. if there are 12 girls in mr. smith's homeroom, how many students are in the whole middle school?

3:4 = G:B

1:5 = Mr. Smith's class: 7th Grade

2:7= 7th: Middle school

12 girls = 3 units

1 unit = 12/3= 4

Boys = 4x4= 16

Whole class = 28 students

Class : Grade = 1:5     7 = number of units in  Mr. Smith's class

28 = 1 unit

5 units= 28x5= 140 There are 140 kids in the grade

140 = 2 units

1 unit = 140/2= 70

70x7=490

There are 490 students in the whole grade

5

step-by-step explanation: