Respuesta :
Answer:
The bank should invest $ 48,000 in bonds.
Step-by-step explanation:
Suppose C, M and B represents the investment in CD, mortgages and bonds respectively,
∵ Total investment = $ 136,000
⇒ B + C + M = 136000 .......(1),
Also, bonds paying 8% CD is paying 7% in mortgages paying 10% the bond,
So, total interest = 8% of B+7% of C+10% of M,
= 0.08B + 0.07C + 0.10M
We have, total interest = $12,040,
0.08B + 0.07C + 0.10M = 12,040
⇒ 8B+7C+10M = 12,04000 .....(2),
Again, the bond and CD investment must equal the mortgage investment,
⇒ B + C = M .......(3),
Equation (1) + equation (3),
2B + 2C = 136000
B + C = 68000 .........(4),
From equation (2) and (3),
8B+7C+10(B+C) = 12,04000
18B + 17C = 12,04000 .....(5)
Equation (5) - 17 × equation (4),
18B - 17 B = 1204000 - 1156000
B = 48000
Hence, the bank should invest $ 48,000 in bonds.
