Answer:
The number of years is
![T =13 \ years](https://img.qammunity.org/2021/formulas/business/college/k5cucy8w8bvhg64jt8jgxf4xr9jiauaoc2.png)
Step-by-step explanation:
From the question we are told that
The total value of the investment A and B is
$40, 000
The future value of A is
$28,000
The time period is t = 3
The expected return of A is
7.1 % = 0.071
The future value of B is
$36,000
The time period for B is T
The expected return of B is
5.5 % = 0.055
The present value of investment A is mathematically represented as
substituting values
$ 22792.38
The present value of B is mathematically evaluated as
![B = k - A](https://img.qammunity.org/2021/formulas/business/college/x32lyyb5pbjc9h7ehu0hhiwikbjb02ttlk.png)
substituting values
B = 40, 000 - 22792.38
B = $17,208
The future value of B is
![F_B = B * (1 + e_B)^T](https://img.qammunity.org/2021/formulas/business/college/cqasra0d13ldopvtlwa69j4utnj3oqr8l3.png)
substituting values
![36,000 =17,208 * (1 + 0.055)^T](https://img.qammunity.org/2021/formulas/business/college/r3a9mkydpmlge6rbirudmgt348dlqhnqgz.png)
![2.0921 = (1.055)^T](https://img.qammunity.org/2021/formulas/business/college/8736s4zan776knvnrayvltse7suxru7jzy.png)
take log of both sides
![log(2.0921) =log (1.055)^T](https://img.qammunity.org/2021/formulas/business/college/cwri4r9na67ouz89bf5onz3xi0kehk27t6.png)
![0.32057 = T log (1.055)](https://img.qammunity.org/2021/formulas/business/college/3a3sctum77nrkyk10u3mls273fsq459urn.png)
=>
![T =13 \ years](https://img.qammunity.org/2021/formulas/business/college/k5cucy8w8bvhg64jt8jgxf4xr9jiauaoc2.png)