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

Hence, the correct option is Option D.