Question

A person deposited Rs. 5000 in his saving account. The amount is set to increase by $(\frac{1}{10}{)}_{th}$ of itself every two years. What would be the maturity amount (in Rs.) of investment after the $2^{nd}$, $4^{th}$, $6^{th}$ and $8^{th}$ year respectively? Are these in AP?

• A. 5000, 6000, 7000, 8000, Yes
• B. 500, 1000, 1500, 2000, Yes
• C. 5500, 6000, 6500, 7000, No
• D. 5500, 6050, 6655, 7320.5, No

Answer 1

The correct option is D 5500, 6050, 6655, 7320.5, No

For the first two years, increment in the amount = $Rs.\frac{1}{10}\times 5000=Rs.500$

$\therefore$ The amount after 2 years would be Rs. 5500.
Similarly, the maturity amount after the $2^{nd}$, $4^{th}$, $6^{th}$ and $8^{th}$ years would be Rs. 5500, Rs. 6050, Rs. 6655, Rs.7320.50

Difference between first two terms = Rs.6050 - Rs.5500 = Rs.550

Difference between third and second terms = Rs. 6655 - Rs. 6050 = Rs. 605

Since $a_2–a_1\ne a_3-a_2,$ the sequence of the maturity amounts does not form an A.P..