Question

Cost of textbook is 8 more than one third the cost of notebook.Deduce this statement into linear equation in two variables. Also what will be the cost of notebook when cost of textbook is $\$12$.

• A. $x=y+\frac{8}{3}$, Where $x$ is cost of textbook and $y$ is cost of notebook
• B. $x=\frac{y}{3}+8$, Where $x$ is cost of textbook and $y$ is cost of notebook
• C. Cost of notebook will be $\$12$
• D. Cost of notebook will be $\$10$

Answer 1

Answer: (B), (C)

Cost of notebook will be $\$12$

Let cost of textbook be $x$ dollars.
And cost of note book be $y$ dollars.
According to statement $x$ is $8$ more than $\frac{y}{3}$
$\Rightarrow x=8+\frac{y}{3}$
This is linear equation for above statement.

When $x=\$12$
$\Rightarrow 12=8+\frac{y}{3}\Rightarrow 4=\frac{y}{3}\Rightarrow y=\$12$