Cassandra invested one part of her $10,000 at 7.5% per year and the other part at 8.5% per year. Her income from the two investment was $820. How much did she invest at each rate? Answers:
A) x = $2000 and y = $7000
B) x = $4000 and y = $7000
C) x = $3000 and y = $7000
D) x = $5000 and y = $7000
E) x = $6000 and y = $7000
Let x and y be the amount invested at 7.5% and 8.5% respectively   Income = $820 = 7.5% * x + 8.5% * y   The total amount invested is also known   10,000 = x + y   Solve the system of the equations to find x and y.   x = $3000 and y = $7000   Answer x = $3000 and y = $7000
<result>C</result>
Cassandra invested one part of her $10,000 at 7.5% per year and the other part at 8.5% per year. Her income from the two investment was $820. How much did she invest at each rate?