How long will it take for a sum of money to double itself at 10 simple interest?

Answer

Nội dung chính Show

• In how many years will a sum of money double itself at 10% per annum simple interest?
• Answer (Detailed Solution Below)
• Let sum of money be P=100Interest per annum =10% amount = 2× 100 = 200 simple interest = 200 - 100 = 100Since, SI=PTR100⇒T=100×SIPR=100×100100×10∴t=10 years.
• In what time will a sum of money double itself at 25 4 Pa?
• At what rate of simple interest will be sum double itself in 25 years?
• In what time will a sum double itself at 4% per annum at simple interest?
• How many years will a sum of money double itself at 18.75% per annum simple interest?

Nội dung chính Show

• In how many years will a sum of money double itself at 10% per annum simple interest?
• Answer (Detailed Solution Below)
• Let sum of money be P=100Interest per annum =10% amount = 2× 100 = 200 simple interest = 200 - 100 = 100Since, SI=PTR100⇒T=100×SIPR=100×100100×10∴t=10 years.
• In what time will a sum of money double itself at 25 4 Pa?
• At what rate of simple interest will be sum double itself in 25 years?
• In what time will a sum double itself at 4% per annum at simple interest?
• How many years will a sum of money double itself at 18.75% per annum simple interest?

Hint: We have to find the percentage of rate at which the sum doubles itself in $6\dfrac{1}{4}$years. So, we will assume the initial amount as ‘x’. And we will also use a simple interest formula. By substituting all the required values in the formula as simplifying the equation, we will get the answer.

Complete step-by-step answer:
Assume the principal amount is $x$.
The principal amount doubles itself. So, it will become $2x$.
Money from interest will be $ = 2x - x$$ \Rightarrow x$
Assume the rate of interest as ‘r’.
Now, we will use a simple interest formula. But first we will discuss it. Simple interest is a method to calculate the amount of interest charged on a sum at a given rate and for a given period of time. Simple interest is calculated with the following formula
$S.I. = P \times R \times T$where P = Principal, R = Rate of Interest in % per annum, and T = Time usually calculated as the number of years. The rate of interest is in percentage r % and is to be written as $\dfrac{r}{{100}}$.
$S.I. = P \times R \times T$
Substituting the values in formula.
$x = \dfrac{{x \times r \times 6\dfrac{1}{4}}}{{100}}$
$100 = r \times \dfrac{{25}}{4}$
$400 = r \times 25$
$r = \dfrac{{400}}{{25}}$
$r = 16\% $
So, the rate is 16%.
So, the correct answer is “Option B”.

Note: Whenever this type of question is asked we will find the interest on principal amount by subtracting principal amount from the money after the number of years given in the question and then we will assume rate of interest to be r and then apply, Simple Interest formula and find the required value of rate of interest.

In how many years will a sum of money double itself at 10% per annum simple interest?

1. 4 years
2. 8 years
3. 10 years
4. 6 years

Answer (Detailed Solution Below)

Option 3 : 10 years

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Given:

the sum of money doubles itself.

Rate = 10% 

Concept used:

 S.I. = PRT/100

Amount = P + SI

Calculation:

Amount = 2P = P + P

Let the Principal be 100, then Simple Interest = 100

⇒ 100 = (100 × 10 × T)/100

⇒ T = 10 years

∴ Time taken is 10 years.

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In how many years will a sum of money double itself at 10 %.Interest per annum.

Solution

Let sum of money be P=100Interest per annum =10% amount = 2× 100 = 200 simple interest = 200 - 100 = 100Since, SI=PTR100⇒T=100×SIPR=100×100100×10∴t=10 years.

In what time will a sum of money double itself at 25 4 Pa?

Answer. (d) 16 Years ans.

At what rate of simple interest will be sum double itself in 25 years?

Detailed Solution The Sum of money doubles itself in 25 years. Concept: Simple interest is the interest calculated on the principal portion of the loan or the original contribution to the saving account. ∴ The rate of interest per annum is 4%.

In what time will a sum double itself at 4% per annum at simple interest?

=(x×4100×x)years = 25 years.

How many years will a sum of money double itself at 18.75% per annum simple interest?

∴ In 5 years 4 months the amount will be doubled at a rate of 18.75% simple interest per year.

At what rate of simple interest will a sum double itself in 10 years?

How many years will it take for a sum of money to double at 10% compounded annually?

In what time will a sum of money doubles itself at 10 per annum compound interest payable half yearly?