math q! (1 Viewer)

Lemonlime

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someone invests $2000 at 9% per year compound interest, compounded monthly. calculate the total interest earned by the investment after 6 years.


answer: 4 (...WHY?!)

i got something like $3425.11 ... o_O
 

Uniqueness

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Are you sure that's the right answer? Maybe it's for a different question? Which book is it from? It doesn't even look logical -_-
 

Shadowdude

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$3425.11 isn't the interest earned, that's just the amount the $2000 grows to after 6 years.

The interest earned would be $3425.11 - $2000 = $1425.11. Right?
 

zombies

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$3425.11 isn't the interest earned, that's just the amount the $2000 grows to after 6 years.

The interest earned would be $3425.11 - $2000 = $1425.11. Right?
Haha my bad, yes Shadow is right :p
 

Uniqueness

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$3425.11 isn't the interest earned, that's just the amount the $2000 grows to after 6 years.

The interest earned would be $3425.11 - $2000 = $1425.11. Right?
yeesshh. Can you please figure out where i did wrong? :/
 

Shadowdude

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yeesshh. Can you please figure out where i did wrong? :/
Well, what's your working?


$2000 at 9% per year compound interest, compounded monthly. That is, (9/12)% = 0.75% per month. 6 years is 72 months.

So in 6 years, the compounding will make the $2000 worth:



We put in $2000 originally, so we subtract the $2000 to get the pure interest.
 

Uniqueness

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Well, what's your working?


$2000 at 9% per year compound interest, compounded monthly. That is, (9/12)% = 0.75% per month. 6 years is 72 months.

So in 6 years, the compounding will make the $2000 worth:



We put in $2000 originally, so we subtract the $2000 to get the pure interest.
Oh got it. Stupid mistake. I divided 9% instead of 9 >_<
 

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