Explanation:

- When a shopkeeper sells two articles at the same selling price, one with a gain and the other with a loss of the same percentage, there is an overall loss.

- Let's first calculate the cost price for each.

- Gain scenario: Selling Price (SP) = Rs 9,879 = Cost Price (CP) * (1 + 11/100)

- Loss scenario: Selling Price (SP) = Rs 9,879 = Cost Price (CP) * (1 - 11/100)

- Solving gives:

- CP of first article = Rs 8,900

- CP of second article = Rs 11,100

- Total SP = 9,879 + 9,879 = Rs 19,758

- Total CP = 8,900 + 11,100 = Rs 20,000

- Overall loss = Total SP - Total CP = -Rs 242

- Overall percentage loss = (242/20,000) * 100 = 1.21%

Correct Answer: Option 3: 1.21% loss