# Ex.8.2 Q11 Comparing Quantities Solution - NCERT Maths Class 8

## Question

An article was purchased for \(\rm{Rs}\, 1239\) including GST of \(18\%\). Find the price of the article before GST was added?

## Text Solution

**What is known?**

Price of article including GST \(= \rm{Rs}\, 1239\)

GST \(= 18\%\)

**What is unknown?**

Price of the article before GST was added.

**Reasoning:**

GST is \(18\%\), initial price (before GST was added) \(+\) GST is \(\rm{Rs}\, 1239.\)

Assuming initial price as *\(x\)*, and using above, *\(x\)* can be calculated.

**Steps:**

Let the price of the article before GST was added be *\(x\)*

GST \(\%\) \(=\) \(18\%\)

GST \(=\) \(18\%\) of initial price of article

Then, initial price of article \(+\) GST \(= 1239\)

\[\begin{align}x + 18\% \times x &= 1239\\x + \frac{{18}}{{100}}x &= 1239\\\frac{{{118}}}{{{100}}} \times x &={1239}\\x&= \frac{{{1239 \times 100}}}{{{118}}}\\x& = 1050\end{align}\]

Price of the article before GST was added is \(\rm{Rs}\, 1050\)