sat suite question viewer
An investment account was opened with an initial value of . The value of the account doubled every years. Which equation represents the value of the account , in dollars, years after the account was opened?
Explanation
Choice C is correct. It's given that represents the number of years since the account was opened. Therefore, represents the number of -year periods since the account was opened. Since the value of the account doubles during each of these -year periods, the value of the account can be found by multiplying the initial value by factors of . This is equivalent to . It's given that the initial value of the account is . Therefore, the value of the account , in dollars, years after the account was opened can be represented by .
Choice A is incorrect. This equation represents the value of an account if the value of the account halves, not doubles, every years.
Choice B is incorrect. This equation represents the value of an account if the value of the account decreases by , not doubles, every , not , years.
Choice D is incorrect. This equation represents the value of an account if the value of the account increases by a factor of , not doubles, every , not , years.