To solve this problem, plug 8250 in for b and 15 in for t and then solve for k:
![8250=1000e^(15k)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xdqbzyk2gqxkqfupodvh2o9oej4992supb.png)
*Divide both sides by 1000*
![8.25=e^(15k)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/q7wgn7sbp93q1hrgyk4omxb0jnwsvfuaca.png)
*Take the natural log (ln) of both sides*
2.1102=15k
*Divide both sides by 15*
0.1406=k
0.1406 rounds to 0.141 which is close to a. 0.143.
Hope this helps!!