Question

Part 1) You deposit $100 in a bank account that earns 5% interest, compounded monthly.

Answer 1

1) A=100(1+0.05/12)^12t
2) 125=100(1+0.05/12)^12t
125/100=(1+0.05/12)^12t
Log(125/100)=12t*log(1+0.05/12)
12t=log(125÷100)÷log(1+0.05÷12)
t=[log(125÷100)÷log(1+0.05÷12)]/12
T=4.5 years