Question : At a certain rate of interest per annum, compounded annually, a certain sum of money amounts to two times itself in 11 years. In how many years will the sum of money amount to four times itself at the previous rate of interest per annum, also compounded annually?
Option 1: 20 years
Option 2: 5.5 years
Option 3: 22 years
Option 4: 33 years
New: SSC MTS 2024 Application Form OUT; Direct Link
Don't Miss: Month-wise Current Affairs | Upcoming Government Exams
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 22 years
Solution : Present value = $P(1+\frac{r}{100})^n$, where $P$ is the principal, $r$ is the annual interest rate and $n$ is the time in years. Let the sum of money be $P$ and the interest rate is $r$. The amount after 11 years is, $2P=P(1+\frac{r}{100})^{11}$ ⇒ $(1+\frac{r}{100})=2^{\frac{1}{11}}$ Let the amount be increased to four times after n years. ⇒ $4P=P(1+\frac{r}{100})^n$ ⇒ $4=(2^{\frac{1}{11}})^n$ ⇒ $2^2=2^{\frac{n}{11}}$ ⇒ $2=\frac{n}{11}$ ⇒ $n=22$ Hence, the correct answer is 22 years.
Application | Cutoff | Selection Process | Preparation Tips | Eligibility | Exam Pattern | Admit Card
Question : A certain sum of money amounts to 3 times itself in 13 years when interest is compounded annually at a certain interest rate per annum. In how many years will the initial sum amount to 9 times itself at the same interest rate per annum, also compounded annually?
Question : A certain sum of money amounts to $\frac{3}{2}$ of itself in 2 years applying simple interest. Find the rate of simple interest per annum.
Question : On a certain sum of money, the simple interest for 2 years is INR 150 at the rate of 10% per annum. What is the difference between compound interest and simple interest for 2 years if, in the case of compound interest, interest is compounded annually at the rate of 10% per
Question : A sum invested at a certain rate of interest per annum, compounded annually, amounts to INR 14,400 in 2 years and to INR 25,920 in 4 years. What is the sum invested?
Question : A sum invested at a certain rate of interest per annum, compounded annually, amounts to INR 3,600 in 2 years and to INR 6,480 in 4 years. What is the sum invested?
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile