Final answer:
To find the selling price per piece of cake, add the cost of making the cake (Tk. 400) to the profit (Tk. 200), giving a total of Tk. 600. Divide this by the number of pieces (12) to get the selling price of Tk. 50 per piece.
Step-by-step explanation:
The question asks to calculate the selling price of each slice of cake, assuming the baker wants to make a profit on the entire cake. First, we calculate the total selling price by adding the cost of making the cake to the desired profit, which is Tk. 400 + Tk. 200 = Tk. 600. Next, we determine the selling price per piece by dividing the total selling price by the number of pieces, resulting in Tk. 600 / 12 pieces = Tk. 50 per piece.