Mathematics

# How long will lucy have to wait before her $2500 invested at 6% earns$600 ?

$\2500+\600=3100\\\\\100\%+6\%=106\%=1.06\\\\\2500\cdot1.06^n=\3100\ \ \ /:\2500\\\\1.06^n=1.24\\\\log_{1.06}1.06^n=log_{1.06}1.24\\\\n=log_{1.06}1.24\\\\n\approx4\ (years)$