linear equations

Question

You have 3 bank accounts. The first pays 1%, the 2nd pays 2%, and the 3rd pays 3%. You have
twice as much invested in the second account as the first. You have $35,000 invested between
the 3. If you earn $850 total between the three, how much is invested in the account paying
2%?

Answer 1

$10000 is the amount invested earning 2% interest

 

x + y+z = 35000

 

y= 2x

 

thus, 3x + z = 35000 (this is equation 1)

 

Interest at 1% = .01 and .02 and .03 respectively

 

Thus, 

.01x+ .02(2x) +.03Z = 850

 

.05x +.03Z = 850 (this is equation 2)

 

Solving equation 1 and 2 results in x= 5000, y=10000 and z = 20000.

Interest is $50, 200 and 600 accordingly for x, y, and z

 

Hope this helps