Word Problems Help

Question

A mother wants to invest 11,000.00 for her son's future education. She invests a portion of the money in a bank certificate which earns 4% and the remainder in a savings bond that earns 7%. if the total interest earned after one year is 660.00 how much money did she invest in the account?

Answer 1

Here's what we know:

c + s = 11000 (the certificate and savings invested equals $11000)

.04c + .07s = 660 (the interest earned is $660)

 

Multiply the second equation by -25:

c   +   s   =  11000

-c - 1.75s = -16500

----------------------

-.75s = -5500

Divide both sides by -.75

s = 7333.33

 

c + 7333.33 = 11000

c = 3666.67

 

.04 * 3666.67 + .07 * 7333.33 = 660

146.67 + 513.33 = 660

660 = 660