Quant Exam  >  Quant Questions  >  A sum of amount at r% compound interest doubl... Start Learning for Free
A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k? 
  • a)
    10 
  • b)
  • c)
  • d)
  • e)
    None of these
Correct answer is option 'D'. Can you explain this answer?
Verified Answer
A sum of amount at r% compound interest doubles in 3 years. In 9 years...
View all questions of this test
Most Upvoted Answer
A sum of amount at r% compound interest doubles in 3 years. In 9 years...
Given data:
Amount at r% CI doubles in 3 years.
So, the CI earned annually will be r/100.
Using the formula for CI:
Amount = P(1 + r/100)^n
2P = P(1 + r/100)^3
(1 + r/100)^3 = 2
1 + r/100 = ∛2
r/100 = (∛2 - 1)
r = 100(∛2 - 1)

Now, we need to find the value of k when the amount will be k times of the original principal in 9 years.

Using the formula for CI:
Amount = P(1 + r/100)^n
Amount = P(1 + (∛2 - 1))^9
Amount = P(∛2)^9
Amount = 2.828P

So, the amount after 9 years will be 2.828 times the original principal.
Therefore, the value of k will be 2.828/1 = 8.

Hence, the correct answer is option D (8).
Explore Courses for Quant exam
A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer?
Question Description
A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? for Quant 2024 is part of Quant preparation. The Question and answers have been prepared according to the Quant exam syllabus. Information about A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Quant 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer?.
Solutions for A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Quant. Download more important topics, notes, lectures and mock test series for Quant Exam by signing up for free.
Here you can find the meaning of A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A sum of amount at r% compound interest doubles in 3 years. In 9 years it will be k times of the original principal. What is the value of k?a)10b)9c)6d)8e)None of theseCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Quant tests.
Explore Courses for Quant exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev