SOLUTION: Douglas invests money in two simple interest accounts. He invests three times as much in an account paying 14% as he does in an account paying 5%. If he earns $152.75 in interest i

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Question 1186851: Douglas invests money in two simple interest accounts. He invests three times as much in an account paying 14% as he does in an account paying 5%. If he earns $152.75 in interest in one year from both accounts combined, how much did he invest altogether?
Total Principal in Both Accounts = $

Found 3 solutions by mananth, ikleyn, greenestamps:
Answer by mananth(16946)   (Show Source):
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Douglas invests money in two simple interest accounts. He invests three times as much in an account paying 14% as he does in an account paying 5%. If he earns $152.75 in interest in one year from both accounts combined, how much did he invest altogether?
Total Principal in Both Accounts = $
an account pays 5% Assume the amount is $x ( 0.05)
Second account will be 3x @ 14% (0.14)
he earns $152.75 in interest in one year
Interest equation
0.05x + 0.14(3x) = 152.75
0.05x +0.42x =152.75
0.47x = 152.75
x = 152.78/0,47
x = 325.06
3x = 3*325.06 =975.18

Answer by ikleyn(52775)   (Show Source):
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.

Interest equation 0.05x + 0.14(3x) = 152.75 0.05x + 0.42x = 152.75 0.47x = 152.75 x = 152.75/0.47 x = 325 3x = 3*325 = 975 Altogether 325 + 975 = 1300 dollars. ANSWER

Solved.

Answer by greenestamps(13198)   (Show Source):
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Since he invested 3 times as much at 14% as at 5%, his weighted average percent return was

(3(14)+1(5))/4 = 11.75

Since he earned $152.75 in interest, the total amount invested was

$152.75/.1175 = $1300

ANSWER: $1300