Discount percent is a measure of how much an item's price is reduced from its original price. To find the discount percent, we need to compare the difference between the original price and the discounted price.

Given that the item was marked at Rs. 840 and sold for Rs. 714, we can calculate the discount amount using the formula:

Discount Amount = Original Price - Discounted Price

Substituting the given values into the formula, we have:

Discount Amount = Rs. 840 - Rs. 714 = Rs. 126

To find the discount percent, we divide the discount amount by the original price and multiply by 100:

Discount Percent = (Discount Amount / Original Price) * 100

Substituting the values, we have:

Discount Percent = (Rs. 126 / Rs. 840) * 100 = 15%

Therefore, the correct answer is option A) 15%.

Explanation:
To find the discount percent, we need to compare the difference between the original price and the discounted price. In this case, the original price is Rs. 840 and the discounted price is Rs. 714. The discount amount is calculated by subtracting the discounted price from the original price: Rs. 840 - Rs. 714 = Rs. 126.

To find the discount percent, we divide the discount amount by the original price and multiply by 100. So, (Rs. 126 / Rs. 840) * 100 = 15%. Therefore, the discount percent is 15%.

The discount percent represents the percentage by which the original price has been reduced. In this case, the item was sold at a 15% discount, meaning the customer paid only 85% of the original price.