Given:
Selling price of the chair = $1504
Marked price of the chair = $1880

To find:
Rate of discount allowed on the chair

Solution:

To find the rate of discount, we need to calculate the actual discount amount first. The discount amount is the difference between the marked price and the selling price.

Discount = Marked price - Selling price

Step 1: Calculate the discount amount
Discount = $1880 - $1504 = $376

Step 2: Calculate the rate of discount
Rate of discount = (Discount / Marked price) * 100

Rate of discount = ($376 / $1880) * 100

Rate of discount = (0.2) * 100

Rate of discount = 20%

Explanation:
The rate of discount allowed on the chair is 20%. This means that the customer received a 20% reduction in the marked price and paid only 80% of the original price for the chair.

The discount amount is calculated by subtracting the selling price from the marked price. In this case, the discount amount is $376.

To find the rate of discount, we divide the discount amount by the marked price and multiply by 100. This gives us the percentage reduction in the price.

In this example, the rate of discount is 20%, which means the customer paid only 80% of the original price for the chair.