Well I can see where you have the issue. This is actually a simple fraction problem. Let's begin.
Step 1: Determine the prices of the fabric, per every 10th of a meter.
Since we know that 10/10 of a meter=1 meter, divide 3.30 by 10 to get the price per 10th of a meter which is .33.
Step 2: Determine the price of the blue fabric.
Since the blue fabric requires 2.3 meters (or 23/10) we can multiply .33 by 23 and have the pricing for the blue fabric, which is 7.59.
Step 3: Determine the price of the white fabric.
Since we know that there is 3.5 meters of white fabric (or 35/10) we can multiply .33 by 35 and again have the pricing, which is 11.55.
Step 4: Determine the price of the red fabric.
Since we know that the costume requires 0.6 meters of red fabric (or 6/10) we multiply .33 by 6 and get the pricing for red, which is 1.98.
Step 5: Add these three numbers up to get the total price of the costume.
7.59+11.55+1.98=21.12
Step 6: Subtract the cost of the fabric from the total budget to see how much money Kelly has left.
40.00-21.12=18.88
Since the problem does not specify any other costs other than the fabric and accessories, the assumed amount left for accessories is C: $18.88