[tex]100\%+5\%=105\%=1.05\\\\\#0-40\\\#1-40\cdot1.05=42\\\#2-40\cdot1.05\cdot1.05=40\cdot1.05^2=44.1\\\#3-40\cdot1.05\cdot1.05\cdot1.05=40\cdot1.05^3=46.305\\\vdots\\\text{therefore}\\\#12-40\cdot1.05^{12}\approx71.834\approx72\\\\\text{Answer:}\ 72[/tex]
