Question

Sandeep deposited Rs. 5000 in his saving account. His amount increases by 1/10 times of itself after every two years. What are the maturity amounts (in Rs.) of investment after $2^{nd}$, $4^{th}$, $6^{th}$ and $8^{th}$ years respectively? Are the maturity amounts (in Rs.) after $2^{nd}$, $4^{th}$, $6^{th}$ and $8^{th}$ years the terms of an AP?

• A. 5000, 6000, 7000, 8000, Yes
• B. 500, 1000, 1500, 2000, Yes
• C. 5500, 6000, 6500, 7000, No
• D. 5500, 6050, 6655, 7320, No

Answer 1

The correct option is D

5500, 6050, 6655, 7320, No

Increment in his saving = $\frac{1}{10}\times$ Maturity amount

The maturity amount (in Rs.) of investment of Rs. 5000 after $2^{nd}$, $4^{th}$, $6^{th}$ and $8^{th}$ years will be

5500, 6050, 6655, 7320.

Difference between first two consecutive terms = 6050 - 5500 = 550

Difference between third and second consecutive terms = 6655 - 6050 = 605

Since $a_2–a_1\ne a_3-a_2\ne a_4-a_3$

$\therefore$ This series is not an AP.