Question

Samantha invests a total of $18,000 in two accounts paying 4% and 10% simple interest, respectively. How much was invested in each account if, after one year, the total interest was $1,650.00. A) Enter an equation that uses the information as it is given that can be used to solve this problem. Use z as your variable to represent the amount of money invested in the account paying 4% simple interest. Equation:

Answer 1

Given :

Total investment = $18,000

There are two accounts paying: 4% and 10%

Let the money invested in the account of 4% = z

so, the remaining time invested in the account of 10% = 18000 - z

After one year, the total interest was $1,650.00

So, the equation that can be used is as following :

4% of z + 10% of (18000 - z) = 1650

`\text{0}.04z+0.1(18000-z)=1650`

solve the equation to find z :

`\begin{gathered} 0.04z+0.1\cdot18000-0.1z=1650 \\ -0.06z+1800=1650 \\ -0.06z=1650-1800 \\ -0.06z=-150 \\ \\ z=(-150)/(-0.06)=2500 \end{gathered}`

So, the amount of money of the account of 4% = $2,500

And the other of 10% = 18,000 - 2,500 = $15,500