Michael perez deposited a total of $2000 with two savings institutions. one pays interest at a rate of 6%/year, whereas the other pays interest at a rate of 7%/year. if michael earned a total of $136 in interest during a single year, how much did he deposit in each institution? (let x and y denote the amount of money, in dollars, invested at 6% and 7%, respectively.)

Respuesta :

Answer:

Amount invested at a rate of 6% = [tex]\$400[/tex]

Amount invested at a rate of 7% = [tex]\$1600[/tex]

Explanation:

Let x and y denote the amount of money, in dollars, invested at 6% and 7%, respectively.

Total amount deposited = $2000

[tex]x+y=2000[/tex]

[tex]x=2000-y[/tex]

Interest earned on amount [tex]x[/tex] = [tex]\frac{6}{100}x[/tex]

Interest earned on amount [tex]y[/tex] = [tex]\frac{7}{100}y[/tex]

Total interest earned [tex]=\frac{6}{100}x+\frac{7}{100} y[/tex]

As Michael earned a total of $136 in interest during a single year,

[tex]\frac{6}{100}x+\frac{7}{100} y=136\\6x+7y=13600[/tex]

Put [tex]x=2000-y[/tex]

[tex]6(2000-y)+7y=13600\\12000-6y+7y=13600\\12000+y=13600\\y=13600-12000\\y=1600[/tex]

So,

[tex]x=2000-1600=400[/tex]

Amount invested at a rate of 6% = [tex]\$400[/tex]

Amount invested at a rate of 7% = [tex]\$1600[/tex]

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