What is the percent decrease modeled in the function f(x)=0.75(0.15)^x a)15% b)85% c)75% d)60%

The decrease is C: 75% because the number in the parentheses, 0.15, is the percent of how much is left of the original number. To add up to a full 1, that 0.15 would need to be added with 0.75, which translates to 75%.

I’m confused as to what you are asking 66 2/3 percentage wise