Question

a particular investment losses, on average, 2.1 % in value twice a year. which equation represents the amount of money, y, an investor will have after t years if the initial investment is $400?

Answer 1

Given:

2.1 % loses twice a year.

So at first, the initial investment is $400.

Then first year will be,

$\begin{gathered} 1.\text{ }400(1-2.1\%)=400(1-\frac{2.1}{100})=400(1-0.021) \\ 2.\text{ }400(1-0.021)^2 \end{gathered}$

Second year:

$\begin{gathered} 1.\text{ }400(1-0.021)^2\times(1-0.021) \\ 2.\text{ }400(1-0.021)^3\times(1-0.021) \\ . \\ . \\ . \\ So\text{ it is }y=400(1-0.021)^{2t} \end{gathered}$

Hence, the correct option is Option D.