you multiply that number by the percent as a decimal. Say you want to take 20% of ten. Then you would go .2x10 and get 2.
120 decreased to 100 is a decrease of 16.67%
60.8
120
176
The answer is 45 (44.99997).
It decreased by 7.761%
When 180 is decreased by 40% the result is 108.
When 25 is decreased by 20% the result 20.
45
120 decreased to 100 is a decrease of 16.67%
40
20
176
60.8
120
When 40 is decreased by 30% the result is 28.
There will be an overall increase in the first number.