Question

Time
2. The ratio of boys and girls in a school is 5:4. If there are 80 girls, what is the number of boys and also
find the total number of students.​

Answer 1

Given :

• The ratio of boys and girls in a school is 5:4.

• There are 80 girls in the school.

To find :

• Total number of boys and students =?

Step-by-step explanation :

The given Boys to girls ratio is 5 : 4

And number of girls in class are 80.

Which means we have one half of the equation and other half is to be found

5 : 4 : : x : 80

here you can see when you simplify it you will get, x = 100.

Which gives the correct number of girls in class so the Number of boys are 100 .

or another simple process

5 : 4 : : x : 80

here we know the ratio and total number of girls in class and that is 4 is ratio and 80 total girls in class.

Now, 80/4 = 20

which means if you multiply the 5 : 4 by 20 then you will get the total number of boys and girls in school

And that will be 100 : 80.

And hence number of boys in class are 100.

Now,

Total number of students in the school = total number of girls + total number of boys.

Substituting the values, we get,

= 100 + 80

= 180.

Therefore, Total number of students in the school = 180.

Answer 2

Number of boys is 100 & total number of students is 180.

Solution

We have ratio of boys to girls is 5 : 4

Number of girls = 80

Let the number of boys & girls be 5y & 4y respectively.

As number of girls = 80

∴ 4y = 80

⇒ y = 80/4

⇒ y = 20

☢ Number of boys :

⇒ Number of boys = 5y

⇒ Number of boys = 5(20)

⇒ Number of boys = 100

∴ There are 100 boys in the class.

☢ Number of students in class :

⇒ Number of students = 5y + 4y

⇒ Number of students = 9y

⇒ Number of students = 9(20)

⇒ Number of students = 180

∴ There are 180 students in the class.