Original amount 120 and new amount is 30. what is the amount of decrease and percent of decrease

To find how much it was decreased by, subtract the original amount by the new amount:

120 - 30 = 90
So 120 was decreased by 90

First we find what percent 30 is of 120. We do this by dividing the new amount by the original amount, and then multiply by 100 to change the answer from a decimal to a percentage.

30 / 120 x 100 = 25%

This tells us that 30 is 25% of 120. Now we subtract 100% by 25%, to get the percentage decrease:

100 - 25 = 75%


So the amount of decrease was 90 
And the percentage decrease was 75%