Vincente and Ricarda Perez have invested $27,000 in bonds paying 7%. How much additional money should they invest in a certificate of dposit paying 4% simple interest so that the total return on the two investments will be 6%?
2007-09-11 08:24:49 · 3 answers · asked by Jenn 2 in Science & Mathematics ➔ Mathematics
27,000*.07 +.04x = (27000+x).06
1890 +.04x = 1620 + .06 x
270 = .02x
$13,500 = x
2007-09-11 08:34:13 · answer #1 · answered by ironduke8159 7 · 0⤊ 0⤋
let x be the amount of money he invests at 4%
.07(27000) = $1,890 is the total interest he gains at 7%
.04x is the total interest he gains at 4%
1,890 + .04x is the total interest he earns, and this amount is 6% of the sum of his money invest
1,890 + .04x = .06 (27,000 + x)
1,890 = .04x = 1620 + .06x
270 = .02x
x = $13,5000
hope this helps.
2007-09-11 08:44:53 · answer #2 · answered by 7 · 0⤊ 0⤋
0.07x27000 + 0.04X = 0.06(27000+X)
1890 +0.04X = 1620 + 0.06X
0.02X = 270
X = 13500
2007-09-11 08:35:30 · answer #3 · answered by Jabberwock 5 · 0⤊ 0⤋