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 20 and 36 is 16 (|20-36| = 16).

Next, we need to find the average of the two numbers. The average of 20 and 36 is (20+36)/2 = 28.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 20 and 36 is:

|20-36| / ((20+36)/2) x 100
= 16 / 28 x 100
= 57.14%

Therefore, the percentage difference between 20 and 36 is 57.14%. This means that 36 is 57.14% more than 20.