Question

The diagram shows the mass of some parcels on weighing machine.
Find the value of $y$.

• A. $1$
• B. $2$
• C. $3$
• D. $11$

Answer 1

The correct option is A $1$

As per given figure

$2x+y=5$ ........... $\left(i\right)$

$3x+2y=8$ ........... $\left(i\right)$

Multiply equation $\left(i\right)$ by $2$, we get

$2x\times 2+y\times 2=5\times 2$

$\Rightarrow 4x+2y=10$ ......... $\left(iii\right)$

$(4x+2y)-(3x+2y)=10-8$ .......... [Subtracting $\left(i\right)$ and $\left(iii\right)$]

$\Rightarrow 4x+2y-3x-2y=10-8$

$\Rightarrow x=2$

$2\times 2+y=5$ ......... From $\left(i\right)$

$\Rightarrow 4+y=5$

$y=5-4=1$