Let's calculate the total investment made by P and Q. P invests ₹5000 per month for 6 months, so P's total investment is:
\[
5000 \times 6 = 30,000 \, \text{₹}.
\]
Q invests ₹x per month for 8 months, so Q's total investment is:
\[
x \times 8 = 8x \, \text{₹}.
\]
The total investment made by both P and Q is:
\[
30,000 + 8x \, \text{₹}.
\]
The total profit is shared in proportion to the total investment. We are given that Q receives \( \frac{4}{9} \) of the total profit. Therefore, the fraction of the total profit received by Q is the ratio of Q's investment to the total investment, i.e.,
\[
\frac{8x}{30,000 + 8x}.
\]
Since Q receives \( \frac{4}{9} \) of the total profit, we can set up the equation:
\[
\frac{8x}{30,000 + 8x} = \frac{4}{9}.
\]
Cross-multiply to solve for \( x \):
\[
9 \times 8x = 4 \times (30,000 + 8x),
\]
\[
72x = 120,000 + 32x,
\]
\[
72x - 32x = 120,000,
\]
\[
40x = 120,000,
\]
\[
x = \frac{120,000}{40} = 3000.
\]
Thus, the value of \( x \) is ₹3000.