The increase in the price of a certain item was 25% . Then the price was decreased by 20% and then again increased by 10% . What is the resultant increase in the price?

Let the original price of the item be 100 units.

1. First increase: The price is increased by 25%. New price = 100 + (25% of 100) = 100 + 25 = 125 units.

2. Second change: The price is then decreased by 20%. This decrease is applied to the new price (125 units). Decrease amount = 20% of 125 = (20/100) * 125 = (1/5) * 125 = 25 units. Price after decrease = 125 - 25 = 100 units.

3. Third change: The price is again increased by 10%. This increase is applied to the current price (100 units). Increase amount = 10% of 100 = (10/100) * 100 = 10 units. Final price = 100 + 10 = 110 units.

The original price was 100 units, and the final price is 110 units. The resultant increase in price = Final price - Original price = 110 - 100 = 10 units.

To express this as a percentage of the original price: Percentage increase = (Resultant increase / Original price) * 100% Percentage increase = (10 / 100) * 100% = 10%.

Therefore, the resultant increase in the price is 10%.

Analyzing the options: A) 5%: Incorrect. This would imply a smaller net change. B) 10%: Correct, as calculated. C) 12.5%: Incorrect. This could be a result of miscalculation or incorrectly applying percentages. D) 15%: Incorrect. This might arise from simply adding the percentage changes (25 - 20 + 10 = 15), which is an incorrect method for successive percentage changes.

The final answer is B.