हिंदी

The Compound Interest Payable Annually on a Certain Sum for 2 Years is Rs 40.80 and the Simple Interest is Rs 40. Find the Sum and the Rate Percent. - Mathematics

Advertisements
Advertisements

प्रश्न

The compound interest payable annually on a certain sum for 2 years is Rs 40.80 and the simple interest is Rs 40. Find the sum and the rate percent.

योग
Advertisements

उत्तर

Let sum be Rs. P and r % be the rate of interest.
We have t = 2 years, C.I. = Rs.40.80 and S.I. = Rs.40
Since, Simple interest

= `("P" xx "r" xx "t")/(100)`

⇒ 40 = `("P" xx "r" xx 2)/(100)`

⇒ Pr = `(4000)/(2)`

= 2000
Now,
C.I. = A - P

= `"P"(1 + "r"/100)^"t" - "P"`

= `"P"[(1 + "r"/100)]^"t" - 1]`

⇒ 40.80 = `"P"[(1 + "r"/100)^2 - 1]`

⇒ 40.80 = `"P"(1 + "r"^2/10000 + (2"r")/100 - 1)`

⇒ 40.80 = `"P"("r"^2/10000 + (2"r")/100)`

⇒ 40.80 = `"Pr"("r"/10000 + (2)/100)`

⇒ 40.80 = `2000(("r" + 200)/10000)`

⇒ 40.80 = `("r" + 200)/(5)`

⇒ r = 40.80 x 5 - 200
= 204 - 200
= 4
Hence, r = 4%
Now, Pr = 2000

⇒ P = `(2000)/"r"`

 = `(2000)/(4)`
= 500.
Thus, sum is Rs.500 and rate of interest is 4%.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Compound Interest - Exercise 3.2

APPEARS IN

फ्रैंक Mathematics [English] Class 9 ICSE
अध्याय 3 Compound Interest
Exercise 3.2 | Q 11

संबंधित प्रश्न

Simple interest on a sum of money for 2 years at \[6\frac{1}{2} %\] per annum is Rs 5200. What will be the compound interest on the sum at the same rate for the same period?


Find the compound interest at the rate of 5% per annum for 3 years on that principal which in 3 years at the rate of 5% per annum gives Rs 1200 as simple interest.


The interest on a sum of Rs 2000 is being compounded annually at the rate of 4% per annum. Find the period for which the compound interest is Rs 163.20.


In how much time would Rs 5000 amount to Rs 6655 at 10% per annum compound interest?


The difference between the compound interest and simple interest on a certain sum for 2 years at 7.5% per annum is Rs 360. Find the sum.


Find the amount and the compound interest.

No. Principal (₹) Rate (p.c.p.a.) Duration
(Years)
1 2000 5 2
2 5000 8 3
3 4000 7.5 2

A sum is invested at compound interest, compounded yearly. If the interest for two successive years is Rs. 5,700 and Rs. 7,410. calculate the rate of interest.


A certain sum amounts to Rs. 5,292 in two years and Rs. 5,556.60 in three years, interest being compounded annually. Find: the original sum.


Ramesh invests Rs. 12,800 for three years at the rate of 10% per annum compound interest. Find:

  1. the sum due to Ramesh at the end of the first year.
  2. the interest he earns for the second year.
  3. the total amount due to him at the end of the third year.

Find the sum, invested at 10% compounded annually, on which the interest for the third year exceeds the interest of the first year by Rs. 252.


A man borrows Rs.10,000 at 10% compound interest compounded yearly. At the end of each year, he pays back 20% of the amount for that year. How much money is left unpaid just after the second year ?


What sum will amount of Rs. 6,593.40 in 2 years at C.I. , if the rates are 10 per cent and 11 per cent for the two successive years ?


Find the sum on which the difference between the simple interest and compound interest at the rate of 8% per annum compounded annually would be Rs. 64 in 2 years.


Calculate the compound interest on Rs. 15,000 in 3 years; if the rates of interest for successive years be 6%, 8%, and 10% respectively.


Rekha borrowed Rs. 40,000 for 3 years at 10% per annum compound interest. Calculate the interest paid by her for the second year.


Peter borrows ₹ 12,000 for 2 years at 10% p.a. compound interest. He repays ₹ 8,000 at the end of the first year. Find:

  1. the amount at the end of the first year, before making the repayment.
  2. the amount at the end of the first year, after making the repayment.
  3. the principal for the second year.
  4. the amount to be paid at the end of the second year, to clear the account.

Find the amount and the compound interest payable annually on the following :

Rs.25000 for 1`(1)/(2)` years at 10% per annum.


The simple interest on a certain sum for 3 years at 4% is Rs 600. Find the compound interest for the same sum at the same percent and in the same time.


The difference between simple interest and compound interest compounded annually on a certain sum is Rs.448 for 2 years at 8 percent per annum. Find the sum.


The compound interest on ₹ 8000 at 10% p.a for 1 year, compounded half yearly is ____________


The annual rate of growth in population of a town is 10%. If its present population is 26620, then the population 3 years ago was _________


If the compound interest is calculated quarterly, the amount is found using the formula __________


Depreciation value is calculated by the formula, `"P"(1 - "r"/100)^"n"`


A principal becomes ₹ 2028 in 2 years at 4% p.a compound interest. Find the principal


The number of conversion periods in a year, if the interest on a principal is compounded every two months is ___________


Suppose for the principal P, rate R% and time T, the simple interest is S and compound interest is C. Consider the possibilities.

  1. C > S
  2. C = S
  3. C < S

Then


To calculate the growth of a bacteria if the rate of growth is known, the formula for calculation of amount in compound interest can be used.


Find the difference between Compound Interest and Simple Interest on Rs 45,000 at 12% per annum for 5 years.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×