Details of prices of two items P and Q are presented in the above table. The ratio of cost of item P to cost of item Q is 3:4. Discount is calculated as the difference between the marked price and the selling price. The profit percentage is calculated as the ratio of the difference between selling price and cost, to the cost.
The formula for Profit Percentage is:
\[ \text{Profit \%} = \frac{\text{Selling Price} - \text{Cost}}{\text{Cost}} \times 100 \] The discount on item Q, as a percentage of its marked price, is: 
To find the discount on item Q as a percentage of its marked price, we need to first determine the selling price of item Q using the given profit percentage formula. Then, we calculate the discount.
Hence, the discount on item Q as a percentage of its marked price is 10%.