A sum of money at compound interest doubles in 7 years. In how many years will it become 8 times? MCQ with Answer and Explanation

Question

Share Report Error

A sum of money at compound interest doubles in 7 years. In how many years will it become 8 times?

A. 14 years

B. 28 years

C. 21 years

D. 35 years

Answer: Option C

Solution (By JKSSB Mock Tests)

Doubles in 7 years, 8 = 2³, so 7 × 3 = 21 years.

This question belongs to: Maths Compound Interest

Request complete Subject PDF

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Compound Interest Questions

Question #1

Share Report

At what rate percent per annum will Rs. 64000 amount to Rs. 68921 in 3 years, compound interest compounded annually?

A. 5%

B. 6%

C. 2.5%

D. 4%

View Answer & Solution Discuss

Get Complete Subject PDF for Maths

Correct Answer: Option C

Explanation:
Amount/Principal = 68921 / 64000 = (41 / 40)^3. Therefore, 1 + R/100 = 41/40 => R/100 = 1/40 => R = 2.5%.

This question belongs to: Maths Compound Interest

Question #2

Share Report

Find the compound interest on Rs. 10000 for 1 year at 8% per annum, compounded quarterly.

A. Rs. 850.50

B. Rs. 824.32

C. Rs. 800.00

D. Rs. 840.00

View Answer & Solution Discuss

Get Complete Subject PDF for Maths

Correct Answer: Option B

Explanation:
Quarterly rate = 8 / 4 = 2%. Time = 4 quarters. Amount = 10000 * (1 + 2/100)^4 = 10000 * (1.02)^4 = 10000 * 1.082432 = Rs. 10824.32. Compound Interest = 10824.32 - 10000 = Rs. 824.32.

This question belongs to: Maths Compound Interest

Question #3

Share Report

Find the compound interest on Rs. 3000 at 10% per annum compounded half-yearly for 1 year.

A. Rs. 315

B. Rs. 307.50

C. Rs. 322.50

D. Rs. 300

View Answer & Solution Discuss

Get Complete Subject PDF for Maths

Correct Answer: Option B

Explanation:
Half-yearly rate 5%, n=2. A = 3000 × (1.05)² = 3000 × 1.1025 = 3307.50, CI = 3307.50 − 3000 = Rs. 307.50.

This question belongs to: Maths Compound Interest

Explore All Compound Interest MCQs