Question

Micah deposits C dollars in a bank. The deposited amount earns an annual interest rate of r% and becomes D dollars in t years according to the formula Which formulas could be used to calculate t given C,D, and r

Answer 1

t= 100/r [d/c-1]

Answer 2

`t = (100)/(r) [(D)/(C) - 1]`

Explanation:

Assume that the deposited amount C dollars earn r% simple interest annually.

If after t years the deposited amount C dollars grows to D dollars, then we are asked to write a relation using the given terms to calculate t.

Now, using the formula of simple interest we can write

`D = C(1 + (t* r)/(100))`

⇒
`1 + (t * r)/(100) = (D)/(C)`

⇒
`(t * r)/(100) = (D)/(C) - 1`

⇒
`t = (100)/(r) [(D)/(C) - 1]`

So, this is the expression for t. (Answer)