Amother wants to invest $14,000.00 for her sons future education. she invests a portion of the money in a bank certificate of deposit which earns 4% and the remainder in a savings bond that earns 7%. if the total interest earned after one year is $840.00, how much was invested in the cd amount

the amount of money invested in the bank certificate is $4667.

the amount of money invested in the savings bond is $9333

Step-by-step explanation:

Let x represent the amount of money invested in the bank certificate.

Let y represent the amount of money invested in the savings bond.

A mother wants to invest $14,000.00 for her sons future education. She invested a portion

of the money in a bank certificate of deposit and the remainder in a savings bond. This means that

x + y = 14000

The formula for simple interest is expressed as

I = PRT/100

Where

P represents the principal

R represents interest rate

T represents time

Considering the investment in a bank certificate,

P = x

R = 4%

T = 1

I = (x × 4 × 1)/100 = 0.04x

Considering the investment in the savings bond,

P = y

R = 7%

T = 1

I = (y × 7 × 1)/100 = 0.07y

If the total interest earned after one year is $840.00, it means that

0.04x + 0.07y = 840 - - - - - -1

Substituting x = 14000 - y into equation 1, it becomes

0.04(14000 - y) + 0.07y = 840

560 - 0.04y + 0.07y = 840

- 0.04y + 0.07y = 840 - 560

0.03y = 280

y = 280/0.03 = $9333

Substituting y = 9333 into

x = 14000 - y

x = 14000 - 9333

x = $4667

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64