The firm's capital employed is determined using the formula:
\[
Goodwill} = \frac{Super Profit} \times Normal Rate of Return}}{100}
\]
To calculate super profit:
\[
Normal Profit} = \frac{Normal Rate of Return} \times Capital Employed}}{100}
\]
\[
Super Profit} = Average Profit} - Normal Profit}
\]
Let \( C \) represent the capital employed.
\[
Super Profit} = 6,00,000 - \frac{10\% \times C}{100} = 6,00,000 - 0.10C
\]
Substituting this into the goodwill formula yields:
\[
40,000 = \frac{6,00,000 - 0.10C}{10}
\]
\[
40,000 \times 10 = 6,00,000 - 0.10C
\]
\[
4,00,000 = 6,00,000 - 0.10C
\]
\[
0.10C = 6,00,000 - 4,00,000 = 2,00,000
\]
\[
C = \frac{2,00,000}{0.10} = 20,00,000
\]
Therefore, the capital employed in the firm is ₹ 20,00,000.