Question

In a class, the number of girls is x and that of boys is y. Also, the number of girls is 10 more than the number of boys. If the number of boys is 20. Then the number of girls is
a) 30
b) 20
c) 10
d) 0

Answer 1

Hint: In this question we have to find the number of girls in the class. For that we are going to solve using algebraic methods which cover the simple operation of mathematics like addition. That is we will add the number of girls more than boys and the number of boys to get the required answer.

Formulas used:
Number of girls = Number of girls is more than the number of boys + number of boys

Complete step by step answer:
Given let the number of girls in the class be $x$.
Let the number of boys be $$y=20$$
It is also given that the number of girls is $$10$$ more than the number of boys,
That is the number of girls is $$10+y$$
$$\Rightarrow x=10+y$$
We have to find the number of girls in the class.
We have the number of girls = $$10+y$$
$$\Rightarrow x=10+y$$
Now let us substitute the number of boys that is the value of $y$ in the above equation, we get
$$\Rightarrow x=10+20$$
Which on addition we get,
$$\Rightarrow x=30$$

$$\therefore$$ The Number of girls in the class is $$30$$.

Note:
The major factor while finding the number of girls is it is given that 10 girls are more than boys this will lead to the required answer. Suppose we leave a mistake in understanding the statement we will get the wrong answer.