Elena is thinking about putting $200 in a savings account that earns 4% interest compounded semiannually. She wants to keep that money in the account for 4 years. Which of the formulas below can help her calculate how much money she will have at the end of the 4 years?

A. $200(1 + 0.02)8
B. $200(1 + 0.04)4
C. $200(1 + 0.02)4
D. $200(1 + 0.08)2

Question

Elena is thinking about putting $200 in a savings account that earns 4% interest compounded semiannually. She wants to keep that money in the account for 4 years. Which of the formulas below can help her calculate how much money she will have at the end of the 4 years?

 		A.	$200(1 + 0.02)8
 		B.	$200(1 + 0.04)4
 		C.	$200(1 + 0.02)4
 		D.	$200(1 + 0.08)2

anonymous · Answer

@e.mccormick help please

e.mccormick · Answer

Have you seen the formula for compound interest?

anonymous · Answer

no sadly @e.mccormick

jdoe0001 · Answer

$\bf A=P\left(1+\frac{r}{n}\right)^{nt}
\ \quad \
A=\textit{current amount}\
P=\textit{original amount deposited}\to \$200\
r=rate\to 4\%\to \frac{4}{100}\to 0.04\
n=\textit{times it compounds per year, semi-annually}\to 2\
t=years\to 4$

anonymous · Answer

ohhhhh ok now what @jdoe0001  and @e.mccormick

e.mccormick · Answer

Oh, and here I was writing that thing up again.  Hehe.

e.mccormick · Answer

You put in the numbers you were given for the letters and then solve.

jdoe0001 · Answer

well.. plug and chug

e.mccormick · Answer

Well, solve partially.  You just need to get it to the form used in your answers.

anonymous · Answer

ughhhhhhh i hate mathe i keep geeti crazy numbers @e.mccormick

e.mccormick · Answer

When I look at your answers I see two things that are sort of unique: the interest part and the rt part.  Each one is only duplicated once.  So, if you find either of those you will either eliminate half the answers or find the correct answer.

anonymous · Answer

ok thanks @e.mccormick