Quant Exam  >  Quant Questions  >  Find the least number of integral years in wh... Start Learning for Free
Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.

  • a)
    1

  • b)
    4

  • c)
    2

  • d)
    3

Correct answer is option 'B'. Can you explain this answer?
Verified Answer
Find the least number of integral years in which a sum of money invest...
Given Data:


Compound Interest Rate (r): 20% or 0.20



The sum of money is more than doubled.


Concept:


The formula for compound interest is A = P(1+r/n)(nt), where P is the principal amount, r is the annual interest rate, n is the number of times interest is compounded per year, t is the time the money is invested for in years. When compounded annually (n=1), this simplifies to A = P(1+r)t.


Solution:


We know that the formula for compound interest, when compounded annually, is A = P(1 + r)^t. Here, we want to find the smallest whole number for time t so that A > 2P.


Substituting A as 2P and r as 0.20 into the formula, we get, ⇒ 2 = (1 + 0.20)t ⇒ 2 = 1.20t


We can now try different values for t until we reach a number where 1.20t > 2.


Using t = 1, we get 1.201 = 1.20 which is not greater than 2.


Using t = 2, 1.202 = 1.44 which is not greater than 2.


Using t = 3, 1.203 = 1.728 which is not greater than 2.


Using t = 4, 1.204 = 2.0736 which is greater than 2.


Therefore, the least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled is 4 years.
View all questions of this test
Most Upvoted Answer
Find the least number of integral years in which a sum of money invest...
Given:
Rate of interest = 20%
We have to find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.

Solution:
Let us assume that the principal amount invested is P.
After n years, the amount becomes P(1+20/100)^n = P(6/5)^n
Now, we need to find the least value of n such that P(6/5)^n > 2P
Simplifying this inequality, we get (6/5)^n > 2
Taking logarithm on both sides, we get n log(6/5) > log2
Therefore, n > log2/log(6/5)
n > 3.8
The least value of n is 4.

Hence, the correct answer is option (B) 4.
Explore Courses for Quant exam
Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer?
Question Description
Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. 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 Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Quant 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer?.
Solutions for Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. 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 Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer?, a detailed solution for Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Find the least number of integral years in which a sum of money invested at 20% compound interest per annum will become more than double itself.a)1b)4c)2d)3Correct answer is option 'B'. 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