A seller increased price of a product by 30% and allows a discount of 15%. What is his net gain%?

Sure, here is the step by step solution:

Step 1: Let's assume the original price of the product is $100.

Step 2: After a 30% increase, the new price would be $100 + 30$100 = $130.

Step 3: Now, the seller allows a discount of 15% on the new price. So, the discount amount would be 15% of $130 =$19.5.

Step 4: Therefore, the selling price after the discount would be $130 -$19.5 = $110.5.

Step 5: The net gain is the final selling price minus the original price, which is $110.5 -$100 = $10.5.

Step 6: To find the net gain percentage, we divide the net gain by the original price and multiply by 100. So, the net gain percentage is ($10.5 /$100) * 100 = 10.5%.

So, the seller's net gain is 10.5%.