Question 1018952
Call the amount of money invested at 7%, x.
Thus he invested 2x at 10%.
The setup looks like this
.07x + (.10)(2x) = 810
.07x + .20x = 810
.27x = 810
x = 810/.27 = $3000 at 7%  and then
2x = $6000 at 10%