Question

in a class of 40 students the number of girls is 1:3of the number of boys find the number of boys​

Answer 1

Given,

Total number of students in a class = 40

The ratio of number of girls to the number of boys = 1:3

To find,

The number of boys in the class.

Solution,

We can simply solve this mathematical problem using the following process:

Let us assume that the number of girls in the class be x.

According to the question;

The ratio of number of girls to the number of boys in the class = 1:3

=> x / (number of boys in the class) = 1/3

=> number of boys in the class = 3x

Now, according to the question;

Total number of students in a class = 40

=> Total number of girls in the class + total number of boys in the class = 40

=> x + 3x = 40

=> 4x = 40

=> x = 10 = number of girls in the class

Now,

total number of boys in the class

= (Total number of students in the class) - (number of girls in the class)

= 40 - 10

= 30

Hence, there is a total of 30 boys in the class.

Answer 2

Answer:

∴ Number of boys in a class is $30$.

Step-by-step explanation:

• In context with question asked,
• We have to find the number of boys.
• It is given that, total students in a class = $40$
• Ratio of number of girls to the boys = $1:3$
• Let, the number of girls be $x$ and number of boys be $3x$.
• Now, according to given data, the equation becomes

       $x+3x=40$

         ∴  $4x=40$

          ∴ $x=\frac{40}{4}$

           ∴ $x=10$

• ∴ Number of boys = $33\times 10=30$
• ∴ Number of boys in a class is $30$.