Question

If $\frac{x}{0.5}+\frac{y}{0.2}=18$, where $x$ and $y$ are positive integers, then identify the value of $x$.

• A. $1$
• B. $2$
• C. $3$
• D. $4$
• E. $5$

Answer 1

Answer: (D)

$4$

As given, $\frac{x}{0.5}+\frac{y}{0.2}=18$
it can be written as, $\frac{x}{\left(\frac{1}{2}\right)}+\frac{y}{\left(\frac{1}{5}\right)}=18$
$\Rightarrow$ $2x+5y=18$
$\Rightarrow$ $5y=18-2x$
Then, try plugging the value of $x$ to get a corresponding $y$ value that is a positive integer. Choose a value of $x$ in such a way that subtraction of their twice from $18$ be in multiple of $5$.
Use $x$ $=4$ for the eq. $5y=18-2x$
Then, $5y=18-2\times 4$ ; $y=2$
So, we got $y$ $=2$ is an positive integer corresponding to the $x$$=4$
Hence,option $D$ is correct.