If you invested $39,000 for 20 years at 7% interest rate how much would you get?

If it is compounded annually you will get  $150917.69

$${\mathtt{39\,000}}{\mathtt{\,\times\,}}{\left({\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.07}}\right)}^{{\mathtt{20}}} = {\mathtt{150\,917.694\: \!036\: \!960\: \!984\: \!246\: \!2}}$$

Sorry anon, I did not realize that you have done the same thing :/

If you are talking about simple interest compounded annually and never take any money out you would wind up with:

39000 x 1.07^20 =  150,917.69