You invested $9000 in stocks and bonds paying 6% and 7% annual interest at the end of the year the total interest from these investments was $610 how much was the invested at each rate?

he invested $2000 in stocks and $7000 in bonds

Step-by-step explanation:

Let x represent the amount of money invested in stocks.

Let y represent the amount of money invested in bonds.

Total amount of money invested in stocks and bonds is

x + y = 9000

x = 9000 - y - - - - - - - - - 1

The formula for simple interest is expressed as

I = PRT/100

Where

P is the principal or initial amount.

T is the duration in years

R is the number rate.

For the stocks,

R = 6%

T = 1 year

P = x

I = (x × 6 × 1)/100 = 0.06x

For the bonds,

R = 7%

T = 1 year

P = y

I = (y × 7 × 1)/100 = 0.07y

At the end of the year, the total interest from these investments was $610. This means that

0.06x + 0.07y = 610 - - - - - - - -2

Substituting equation 1 into equation 2, it becomes,

0.06( 9000 - y) + 0.07y = 610

540 - 0.06y + 0.07y = 610

- 0.06y + 0.07y = 610 - 540

0.01 y =70

y = 70/0.01 = 7000

x = 9000 - 7000

x = $2000

the expected value of the random variable : 0, 1 and 2

step-by-step explanation: