Here's the question you clicked on:
JamenS
invests $5,000 in an account that pays 6.25% interest per year. After how many years will her investment be worth $10,000?
sounds like a simple interest problem the formula for simple interest is I = Prt in this case P is $5,000; r is 0.0625; I is $10,000 and you're looking for t so just substitute \[\implies 10,000 = (5,000)(0.0625)t\] divide both sides by 5,000 \[\implies 2 = 0.0625 t\] divide both sides by 0.0625 \[\implies 32 = t\] does that help?
how did you get that?
i showed you how to do it. where did you go wrong?
http://finedrafts.com/files/Larson%20PreCal%208th/Larson%20Precal%20CH1.pdf
Oh no no..i there's a mistake.. IIRC this is the formula: \[A_n = P\left(1+\frac{r}{100}\right)^{n} \] where r(rate) = 6.25 , n= n , P = 5000, A_n = 10 000
so you're finding n which is the year
that's for compound interest @Mimi_x3
Compound interest is found by \(A_n - P\)
well i havent done these in a while tho :/
it's okay @Mimi_x3 page 222 and here's a little chapter http://finedrafts.com/files/Larson%20PreCal%208th/Larson%20Precal%20CH3.pdf
hmm..looks like i have to look back at my notes.. how can you tell the differennce if its simple interest and compound interest? :/
simple interest only allows the principal to accrue by the term, that is the n year(s) or month(s) compound interest is better understood this way: let us say you are given a choice to pick between 1 million dollars or 1 cent and is doubled every day for the next 30 days, which one would you pick?
oohh..i got it..because the 5k does not double up or anyother words you only invest 5k..i made a mistake then sorry
here's why banks can rip you off http://www.al6400.com/blog/2006/07/10/a-penny-doubled-everyday/