Chris invested $12,000 at a rate of 4%. how long should he leave his money invested if he wants to earn interest of at least $1,000?

12,000 x 1.04^2 = 12,980. This is the total money he has after 2 years, however the difference is not quite 1,000

12,000 x 1.04^3 = 13,500. The difference after 3years is over a 1000
So the answer is 3 years