If I invest $1,000 today in a Profit-Sharing Plan and earn a 6% return on my money, approximately how long will it take me to double your investment?

Pt = Po + Po*rt = $2000.

1000 + 1000*0.06*t = 2000,
1000 + 60t = 2000,
60t = 2000 - 1000 = 1000,
t = 16.67yrs.