Question

An investment club invested part of $8000 at 10% annual interest the rest at 12%. If the annual income from these investments is $900, how much was invested at each rate

Answer 1

let x be the amount invested at 10%
so the amount invested at 12 % = (8000-x)
0.1x + 0.12(8000-x) = 900
0.1x - 0.12x = 900- 960
0.02x = 60
x = 3000 @ 10%
8000 - 3000 = 5000 @ 12%