Determine the value of Ic (sat) and the value of Rb in a simple circuit
I found out the answer but I am not sure why I have the correct answer. Here is what I did


Ic =BIb
113mA = 80Ib
Ib =113mA/80
Ib = 0,0014125A = 1,41mA
V=RI 
R = V/I
R= 25-0,7/1,141mA // Here is the part that I am confused why must I substract 25-0,7?
R = 17234ohm or 17,23kohm //wich is the correct answer