The value of $(0.99)^{15}$ is

Explanation

Using binomial approximation: $(1 - x)^n \approx 1 - nx + \frac{n(n - 1)}{2}x^2$. Here $x = 0.01$, $n = 15$. So $(0.99)^{15} \approx 1 - 0.15 + 0.00105 = 0.8502$.