Answer: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
