From Statement I:
We know the rate of X is Rs. 20 per kg, but without knowing the quantity of rice X used, we cannot calculate the profit percentage.
From Statement II:
We know the rate of Y is Rs. 13 per kg, but without knowing the quantity of rice Y used, we cannot calculate the profit percentage.
Combining both statements:
We know the rates of both rice types, but to calculate the profit, we also need to know the quantities used to mix the rice.
The profit percentage is calculated using the formula \( {Profit Percentage} = \frac{{Profit}}{{Cost Price}} \times 100 \), where the cost price depends on the quantities used.
Thus, both statements are needed to calculate the profit percentage.