Question

$10$ students of class $X$ took part in a Mathematics quiz. If the number of girls is $4$ more than the number of boys, find the number of boys and girls who took part in the quiz by graphical method.

• A. $2,7$
• B. $6,9$
• C. $3,12$
• D. None of these

Answer 1

The correct option is D None of these

Let number of boys be $x$.

Number of girls be $y$.

Given that total number of student is $10$ so that

$x+y=10$

Subtract $y$ both side we get

$x=10–y$

Plug $y=0,5,10$ we get

$x=10–0=10$

$x=10–5=5$

$x=10–10=0$

Therefore, the required points are $(0,10),(5,5),(10,0)$.

Given that If the number of girls is $4$ more than the number of boys

So that

$y=x+4$

Plug $x=-4,0,4$, and we get

$y=-4+4=0$

$y=0+4=4$

$y=4+4=8$

Therefore, the required points are $(-4,0),(0,4),(4,8)$.

The graph is as shown above:

Since the point of intersection in the above graph is $(3,7)$,

Hence, the number of boys are $3$ and the number of girls are $7$.