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

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 \(\rm{Rs}\, 1050\)