For every 2 teachers there are 30 girl students. for every 3 teachers there are 60 boy students. if there are 432 people in the school how many boys, girls and teachers

Discussion

Girls

For every two Teacher there are 30 girls.

That means that every teacher has 30/2 = 15 girls.

Boys

For every three teachers there are 60 boys

So every teacher must teach 60/3 = 20 boys.

Both

The teacher load for every teacher is 20 + 15 = 35 students.

Proportion

1/35 = T/(432 - T) Remember you have to take out the number of Teachers from the total number of people in the building. Cross multiply.

432 - T = 35T Add T to Both sides.

432 = 35T + T

432 = 36T Divide by 36

T = 432 / 36

T = 12 So there are 12 Teachers in the Building

Girls in the Building

Every teacher teaches 15 girls

1 teacher /12 teachers = 15 girls/x Cross multiply

x = 12 * 15

x = 180 girls are in that school.

Boys in the Building

1 teacher teaches 20 boys

12 teachers teach x

1/12 = 20 / x Cross multiply

12*20 = x

240 = x

There are 240 boys in the building.

Summary For the School

Teachers = 12

Boys = 240

Girls = 180

Nice problem. Thanks for posting.

2nd one in the first row is correct

you probably already have the answer but anyways it's b. 15.0

step-by-step explanation: