SIMPLE AND COMPOUND INTEREST

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SIMPLE AND COMPOUND INTEREST

by pappueshwar » Fri Feb 17, 2012 8:24 am
pls assist in solving the below

$1200 is invested at a given interest rate for two years. The difference between the simple 2-year non-compounded return at the end of the two years and an annually compounded return is $132. What is the interest rate?

OA : A
answer i got : 13

A.10%
B.11%
C.12%
D. 13%
E.14%
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by Anurag@Gurome » Fri Feb 17, 2012 7:25 pm
pappueshwar wrote:pls assist in solving the below

$1200 is invested at a given interest rate for two years. The difference between the simple 2-year non-compounded return at the end of the two years and an annually compounded return is $132. What is the interest rate?

OA : A
answer i got : 13

A.10%
B.11%
C.12%
D. 13%
E.14%
Principal = $1200
Let the interest rate is R.
Simple 2-year non-compounded return at the end of the two years = 1200 + (1200 * R * 2) = 1200 + 2400R

Compounded rate of interest in 2 years = 1200(1 + R)²

Difference = 1200(1 + R)² - (1200 + 2400R) = 132
1200(R² + 2R + 1) - 1200 - 2400R = 132
1200R² = 132
R² = 132/1200 implies R ≈ 0.33, which implies rate ≈ [spoiler]33%[/spoiler], which is none of the options.
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