The velocity of money (\(V\)) is given by the equation:
\[
V = \frac{PY}{M}
\]
Where:
- \( P \) is the price level,
- \( Y \) is the total output (real GDP),
- \( M \) is the money supply.
Step 1: The total value of transactions in the economy is:
\[
PY = 100 \, \text{kg} \times 100 \, \text{Rs/kg} = 10,000 \, \text{Rs}
\]
Step 2: The quantity of money \( M = 500 \, \text{Rs} \).
Step 3: Using the formula for the velocity of money:
\[
V = \frac{10,000}{500} = 20
\]
Thus, the velocity of money is 20.
Final Answer:
\[
\boxed{20}
\]