The transaction yields a 33.33% profit per notebook as the selling price is higher than the cost price by a third of the cost price.
The question involves finding the profit or loss percentage in a transaction where the cost price of 4 notebooks is equal to the selling price of 3 notebooks. We can let the cost price of one notebook be 'C' and the selling price of one notebook be 'S'. Then, 4C = 3S. To find the profit or loss percentage, we need to calculate the profit or loss on one notebook and then divide it by the cost price and multiply by 100 to get the percentage.
Step 1: Find the relation between cost price and selling price. From 4C = 3S, we can solve for S in terms of C, which gives S = (4/3)C.
Step 2: Calculate profit or loss per notebook. If S > C, there's a profit. If S < C, there's a loss. Here, S = (4/3)C implies a profit, as S is greater than C.
Step 3: Calculate the profit percentage. Profit per notebook = S - C = (4/3)C - C = (1/3)C. Profit percentage = (Profit/Cost Price) x 100 = ((1/3)C / C) x 100 = 33.33%.
Therefore, there is a 33.33% profit on each notebook.