Question

S
The number of boys and girls in a class are in the ratio 3:5.
If the number of boys is 12, then
a) What is the number of girls in the class ?
b) Find the total number of students in the class.​

Answer 1

Answer:

a) Number of girls in class = 20

b) Total number of students in the class = 32

Step-by-step explanation:

The number of boys and girls in a class are in the ratio 3:5

Let the -

• number of boys be 3M
• number of girls be 5M.

The number of boys is 12.

According to question,

→ 3M = 12

→ M = 12/3

→ M = 4

So,

$\sf{Number\:of\:boys\:=\:3(4)}$

$\implies\:\sf{12}$

$\sf{Number\:of\:girls\:=\:5(4)}$

$\implies\:\sf{20}$

Also, we have to find the total number of students.

Total number of students = Number of boys + Number of Girls

Substitute the known values above

$\implies\:\sf{12\:+\:20}$

$\implies\:\sf{32}$

Answer 2

AnswEr :

• Boys and Girls in Ratio 3:5
• Boys are 12 in the class

Let the No. of Boys be 3a and Girls be 5a.

• According to the Question Now :

⇝ Number of Boys = 12

⇝ 3a = 12

• Dividing Both term by 3

⇝ a = 4

_________________________________

a) What is the number of girls in the class?

⇒ Number of Girls

⇒ 5a

• [ a = 4 ]

⇒ 5 × 4

⇒ 20

∴ There are 20 Girls in the Class.

b) Find the total No. of students in the class.

⇒ Total Students in the Class

⇒ Boys + Girls

⇒ 3a + 5a

⇒ ( 3 + 5 ) × a

⇒ 8 × a

• [ a = 4 ]

⇒ 8 × 4

⇒ 32

∴ There are total 32 Students in the class.