To find the percentage difference between two numbers, we first need to calculate the absolute difference between them. In this case, the absolute difference between 205 and 185 is 20.

Next, we need to find the average of the two numbers. The average of 205 and 185 is (205+185)/2 = 195.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 205 and 185 is (20/195) x 100 = 10.26%.

Therefore, the percentage difference between 205 and 185 is 10.26%. This means that the difference between the two numbers is 10.26% of their average value.