SOLUTION: Charles invested income in two accounts, one paying 3% annual simple interest and the other paying 2% interest. He earned a total of $11 interest. If he invested three times as muc

Algebra ->  Linear-equations -> SOLUTION: Charles invested income in two accounts, one paying 3% annual simple interest and the other paying 2% interest. He earned a total of $11 interest. If he invested three times as muc      Log On


   

Question 1110410: Charles invested income in two accounts, one paying 3% annual simple interest and the other paying 2% interest. He earned a total of $11 interest. If he invested three times as much in the 3% account as he did in the 2% account, how much did he invest at each rate ?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
For the 3% rate:
(1) +I+=+3P%2A.03%2A1+
For the 2% rate:
(2) +11+-+I+=+P%2A.02%2A1+
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Substitute (1) into (2)
(2) +11+-+.03%2A3P+=+.02P+
(2) +11+-+.09P+=+.02P+
(2) +.11P+=+11+
(2) +P+=+100+
and
+3P+=+300+
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He invested $300 @ 3% and $100 @ 2%
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check:
(1) +I+=+.09P+
(1) +I+=+.09%2A100+
(1) +I+=+9+
and
(2) +11+-+I+=+.02P+
(2) +11+-+I+=+.02%2A100+
(2) +I+=+11+-+2+
(2) +I+=+9+
OK