Question

Solve the problem. A retired couple has $120,000 to invest to obtain annual income. They want some of it invested in safe Certificates of Deposit yielding 5%. The rest they want to invest in AA bonds yielding 12% per year. How much should they invest in each to realize exactly $11,600 per year? 1) $90,000 at 12% and $30,000 at 5% O2) $80,000 at 127. and $40,000 at 5% 3) $80,000 at 5% and $40,000 at 12% 4) $70,000 at 5% and $50,000 at 12%​

Answer 1

ertificates 6.00% per annum ---x

AA bond 11.00% per annum ---y

x + 1 y= 160000 ------------------------1

6.00% x + 11.00% y= 15600

Multiply by 100

6 x + 11 y= 1560000.00 --------2

Multiply (1) by -6

we get

-6 x -6 y= -960000.00