Interest Problem

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Sat Jan 30, 2010 8:31 pm

Interest Problem

by cyrusthegreat » Tue Apr 13, 2010 6:57 pm
If $10000 is invested at x percent simple annual interest for n years, which of the following represents the total amount of the interest earned by this investment in n years?

A. 10000 (x^n)

B. 10000 (x/100)^n

c. 10000n(x/100)

d. 10000(1 + x/100)^n

e. 10000n( 1 + x/100)




The answer is c but I checked it with n=3 and it equals $3000 but in reality, the interest earned would be $3310.
How can this be?

Thanks in advance
Source: — Problem Solving |

User avatar
Master | Next Rank: 500 Posts
Posts: 208
Joined: Sun Sep 28, 2008 12:30 pm
Thanked: 22 times

by neoreaves » Tue Apr 13, 2010 7:04 pm
I am not sure what you mean by "in reality"....are you confusing Compound interest with simple interest ...

C seems to be the right answer

Simple interest = PRT

What formula are you using for the calculation you have done ?

Junior | Next Rank: 30 Posts
Posts: 11
Joined: Sat Jan 30, 2010 8:31 pm

by cyrusthegreat » Tue Apr 13, 2010 8:55 pm
Thanks for your reply.

I'm using FV = PV ( 1 + i)^n

Please show me how this is wrong.

Thanks again

Junior | Next Rank: 30 Posts
Posts: 11
Joined: Sat Jan 30, 2010 8:31 pm

by cyrusthegreat » Tue Apr 13, 2010 9:01 pm
I just realized my mistake.

cheers