Mrs. Carolina. invested $9,000; part at 5%, and part at 8%. The total interest on the investment was $630. How much did she invest at each rate?	Choose the most appropriate option
A) x=$13,000, y =$26,000	B) x=$4,000, y =$8,000	C) x=$2,000, y =$4,000	D) x=$3,000, y =$6,000	E) x=$5,000, y =$10,000
I approached this question like a mixture problem.   I don't like the wordingpartat 5% andpartat 8% because we have variables x and y in the answer choices and I have no idea which one is x or y.   Anyway here's how I did it.   0.05(x) + 0.08(y) = 0.07(x+y)   0.01(y) = 0.02(x)   y = 2x   Note: 0.07(x+y) because $630 is 7% of 9,000   In which answer choice is y = 2(x)   Answer x=$3,000, y =$6,000
<result>D</result>
Mrs. Carolina. invested $9,000; part at 5%, and part at 8%. The total interest on the investment was $630. How much did she invest at each rate?