cell subtraction problem

[prefector]

I want to subtract a percent sum from a cell but must have three choices.
Example if cell is under 25 then subtract 8 percent if over 25 then subtract
9 percent if over 70 then subtract 10 percent. Can anyone tell me a formula
for this or if it is even possible?

 

[Bernard Liengme]

Assuming the cell is A1
=iF(A1<25,a1*92%,if(A1<=70,A1*91%,A1*90%))

btw: this is not a programming question (programming is VBA)
best wishes