Question

Sean has 15,000 to invest she will put some of it into a fund that pays 4.5% annual interest in the rest in a certificate of deposit that pays 1.8% annual interest how much should she invest in each account if she wants to earn 4.05% annual interest on the total amount

Answer 1

Answer:$12500 was invested into the account that pays 4.5% annual interest..

$2500 was invested into the the certificate of deposit that pays 1.8% annual interest..

Step-by-step explanation:

Let x represent the amount invested into the account that pays 4.5% annual interest.

Let y represent the amount invested into the certificate of deposit that pays 1.8% annual interest.

Sean has 15,000 to invest. She will put some of it into a fund that pays 4.5% annual interest and the rest in a certificate of deposit that pays 1.8% annual interest. This means that

x = y + 15000

The formula for simple interest is expressed as

I = PRT/100

Where

P represents the principal

R represents interest rate

T represents time in years

I = interest after t years

Considering the account earning 4.5% interest, the interest would be

I = (x × 4.5 × 1)/100 = 0.045x

Considering the account earning 11% interest, the interest would be

I = (x × 1.8 × 1)/100 = 0.018y

if she wants to earn 4.05% annual interest on the total amount, the amount would be

4.05/100 × 15000 = 607.5

Therefore,

0.045x + 0.018y = 607.5 - - - - - - - - - - -1

Substituting x = 15000 - y into equation 1, it becomes

0.045(15000 - y) + 0.018y = 607.5

675 - 0.045y + 0.018y = 607.5

- 0.045y + 0.018y = 607.5 - 675

- 0.027y = - 67.5

y = - 67.5/- 0.027

y = $2500

x = 15000 - y = 15000 - 2500

x = $12500