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 120 and 150 is 30 (150 - 120 = 30).

Next, we need to find the average of the two numbers. The average of 120 and 150 is (120 + 150) / 2 = 135.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 120 and 150 is (30 / 135) x 100 = 22.22%.

Therefore, the percentage difference between 120 and 150 is 22.22%. This means that 150 is 22.22% more than 120.