The ratio of girls to boys is 7:8. the class has 30 students total. How many boys are there???!!! How do I do this ????!!!
Use a proportion.
8/15 = b/30
Cross multiply and solve for b.
I don't know I need help plz tell me the answer
To find out how many boys are in the class, we need to use the information given about the ratio of girls to boys and the total number of students.
First, let's understand the ratio given. The ratio of girls to boys is 7:8, which means that for every 7 girls, there are 8 boys.
Next, we can set up a proportion to solve for the number of boys. We'll use the total number of students in the class, which is 30, as the denominator of the ratio.
Let x represent the number of girls in the class. Since the ratio is 7:8, we can write the following proportion:
7 girls / 8 boys = x girls / (30 total students)
To solve for x, we can cross-multiply:
7 * (30 total students) = 8 * x
210 = 8x
To isolate x and solve for the number of girls, divide both sides of the equation by 8:
x = 210 / 8
x ≈ 26.25
Since we can't have a fraction of a person in this case, we round down to the nearest whole number. Therefore, there are approximately 26 girls in the class.
To find the number of boys, we subtract the number of girls from the total number of students:
Number of boys = Total number of students - Number of girls
Number of boys = 30 - 26
Number of boys = 4
So, there are 4 boys in the class.