Answer:
Step-by-step explanation:
Let x represent the amount invested at 11%. Then (3000-x) is the amount invested at 8%. The interest difference is ...
0.11x - 0.08(3000 -x) = 216
0.19x -240 = 216 . . . . . . . . simplify
0.19x = 456 . . . . . . . . . . . . add 240
456/0.19 = x = 2400 . . . . . the amount invested at 11%
3000-2400 = 600 . . . . . . . the amount invested at 8%