Question

in a class of 42 childrens there are twice as many girls as boys and twice as many boys as redheads how many redheads are there

Answer 1

Whenever solving such kind of questions, you must always remember to begin with assuming a variable for a quantity which can be easily related with others.

Here,
Let us assume the number of girls be x.

You can take any other variable such as a, b, c, y and z.

We have assumed the value of the number of girls because we can easily express the values of other quantities in terms of the number of girls.

Hence,
Number of boys = 2x
Number of redheads = 2 * 2x = 4x

Given,
Total number of students = 42
x + 2x + 4x = 42
7x = 42
x = 42/7

On solving we get,
x = 6

So,
Number of redheads in the class = 4x = 4*6 = 24

Answer 2

Hello user

Let th number of boys in class be x

So, number of girls be 2x ......... (1)

Also, number of redheads = 4x ......... (2)

According to the question,

x + 2x + 4x = 42

7x = 42

x = 6

So, from eq (2), we get

Number of redheads = 4 × 6 = 24.

HOPE IT WORKS.