Sunil borrows Rs. 2275 and promises to pay back with compound interest at 20% p.a. in 3 early equal installments at the end of first, second and third year. Find the amount of each installment.

A Rs. 1080

B Rs. 864

C Rs. 1036

D Rs. 993

E None of these

Solution

Correct Answer: Option A

The value of 2275 after 3 years = the value of the first installment after 2 year + the value of second installment after 1 year + the value of third installment

Let the amount of installment be x

\(\Rightarrow \;2275\;{\left( {1 + \frac{{20}}{{100}}} \right)^3}\; = \;x\;{\left( {1 + \frac{{20}}{{100}}} \right)^2}\; + \;x\;{\left( {1 + \frac{{20}}{{100}}} \right)^1}\; + \;x\)

\(\Rightarrow \;2275\;\left( {\frac{{216}}{{125}}} \right)\; = \;x\;\left( {\frac{{36}}{{25}}} \right)\; + \;x\left( {\frac{6}{5}} \right)\; + \;x\)

\(\Rightarrow \;2275\;\left( {\frac{{216}}{{125}}} \right)\; = \left( {\frac{{\;36 + 30 + 25}}{{25}}} \right)\;x\)

\(\Rightarrow \;2275\;\left( {\frac{{216}}{{125}}} \right)\; = \;\frac{{91}}{{25}}\;\;x\)

\(\Rightarrow \;x\; = \;\frac{{\;2275 \times 216 \times 25}}{{125 \times 91}}\)

⇒ x = 1080

Hence, Amount of each investment is Rs. 1080

Practice More Questions on Our App!

Download our app for free and access thousands of MCQ questions with detailed solutions