In what time will rupees 6250 amount to rupees 6760 at 8% per annum if the interest is compounded half yearly?

Present value = Rs.6250

Interest rate = 8 % per annum

Time = 1 years

Interest is compounded half-yearly.

Amount (A) = P [1 + (R/2)/100]2n [Where, P = Present value

R = Annual interest rate

n = Time in years]

A = 6250 [1 + (8/2)/100]2

A = 6250 [1 + 4/100]2

A = 6250 [26/25]2

A = 6250 × 26/25 × 26/25

A = 10 × 26 × 26

A = 6760

Amount = Rs.6760

Compound interest = Rs.(6760 – 6250)

= Rs.510

Divakaran gets a CI of Rs.510.


  • question_answer A certain sum invested with interest of 8% per annum, compounded semi-annually amounts to Rs. 6760 at the end of 1 yr. The sum is                                                                                             [SSC (CPO) 2014] A) Rs. 6000                        B) Rs. 6520 C) Rs. 6250            (adsbygoogle = window.adsbygoogle || []).push({}); D) Rs. 6500

    Correct Answer: C

    Solution :

    Let the sum invested be Rs. x.
    Amount at the end of 1 yr = Rs. 6760
    Now, rate of interest = 8% and time duration is 1 yr.
    Given, in the question that the amount is compounded semi-annually, i.e. half-yearly.
    Hence, rate of interest changes to
    \[\frac{R}{2}=\frac{8}{2}\]% =4%
    and time duration becomes \[2t=2\times 1=2\,\,yr\]
    By the formula of compound interest, we get
    Amount \[=P{{\left( 1+\frac{R}{100} \right)}^{t}}\]
    \[\Rightarrow \]\[6760=x{{\left( 1+\frac{4}{100} \right)}^{2}}\]\[\Rightarrow \]\[x=\frac{6760}{{{\left( 1+\frac{1}{25} \right)}^{2}}}\]
    \[\Rightarrow \]   \[x=\frac{6760\times 25\times 25}{26\times 26}=10\times 25\times 25\]
    \[\Rightarrow \]   \[x=6250\]

1. Calculate the simple interest if P = Rs. 4800,   T = 2 years,   R = 8 %?

Sol:
P = 4800Rs,   T = 2 years,   R = 8 % .....(Given)

Simple interest(SI) = PTR/100
= (4800 × 2 × 8)/100
= 48 × 2 × 8
= Rs. 768
Hence Simple interest(SI) is Rs. 768

2. Find the simple interest on Rs. 6250 at 4 % per annum for the period from December 27,2002 to May 22, 2003. Also find the amount ?

Sol:
Given
Principal (P) = Rs. 6250, Rate (R) = 4%,
Time (T) = December 27, 2002 to May 22, 2003
The number of days per which the money was kept may be counted as :

Month December January February March April May
Number of days 4 31 28 31 30 22

Time(T) = (4 + 31 + 28 + 31 + 30 + 22)days
= 146 days
Convert the time into years, so divided with 365
Time(T) = 146/365
= (73 × 2)/(73 × 5)
= 2/5 years
Simple interest(SI) = PTR/100
= [6250 × (2/5) × 4]/100
= (6250 × 2 × 4)/(100 × 5)
= 100
∴ Simple interest(SI) = Rs. 100
Now, amount = simple interest + principal
∴ Amount = 100 + 6250 = Rs 6350

3. At what rate percent per annum will the amount Rs.72 produce an interest of Rs. 115.20 in 2 years?

Sol:
Given that the principal amount (P) = Rs.72, time(T) = 2 years.
The Simple interest (SI) = Rs.115.20
Now we have to calculate the rate per cent at which the Rs.72 will
produce a simple interest of Rs.115.20
We know that SI = PTR/100

115.20 = (72 × 2 × R)/100
72 × 2 × R = 115.20 × 100
R = (115.20 × 100)/(72 × 2)
R = 80%
At 80% of interest the amount Rs.72 will produce a simple interest of Rs.115.20 in 2 years.

4. If Rs.1250 amount to Rs.1550 in 3 years at simple interest, then find the rate of percentage?

Sol :
Given
Principal amount (P) = 1250 Rs, Time(T) = 3 years
Total amount (A) = Rs.1550

Simple interest (SI) = total amount – principal amount
= A – P
= 1550 – 1250
= Rs. 300
Now we have to calculate the rate of interest (R)
Simple interest = PTR/100
300 = (1250 × 3 × R)/100
1250 × 3 × R = 300 × 100
R = (300 × 100)/(1250 × 3)
R = 8%
So, the principal Rs. 1250 at the rate 8% per annum will produce Rs. 300 of simple interest in a period of 3 years.

5. Calculate the simple interest and compound interest if principal = Rs. 6000
Rate = 10% and time period = 2 years ?

Simple interest = PTR/100
= (6000 × 2 × 10)/100
= 600 × 2
= Rs. 1200
Now, we have to calculate the compound interest for 2 years
First we will calculate for the first year
Interest on Rs. 6000 for 1 year at the rate of 10% per annum is
Interest for first year = PTR/100
300 = (6000 × 1 × 10)/100
= Rs. 100
Amount at the end of first year = principal + interest for first year
R = 6000 + 600
R = Rs. 6600
So, Rs. 6600 become the principal amount for the second Year.
Principal for second year (P) = Rs. 6600
Rate of interest (R) = 10%
Time period (T) = 1 year
So, interest for second year = (6600 × 1 × 10)/100
= Rs. 660
Amount at the end of second year = principal + interest for second year
= 6600 + 660
= Rs. 72602
Compound interest = amount at the end of second year – principal
= 7260 – 6000
= Rs. 1260
The interest Rs. 1260 is the compound interest on Rs. 6000 for 2 years at the rate 10%.

6. Find the compound interest on Rs. 8000 at 5% per annum, for 2 years, compounded annually ?

Sol:
Given

Principal amount (P) = Rs. 8000
Time (N) = 2 years
Rate (R) = 5%
Compound interest = P{[1 + (R/100)]N – 1}
= 8000{[1 + (5/100)]2 – 1}
= 8000[(21/20)2 – 1]
= 8000[(441/400) – 1]
= 8000(41/400)
= Rs. 820
Hence, compound interest is Rs. 820

7. What is the amount to be paid on a loan of Rs. 62500 for 3/2 years at 8 % per annum, compounded half – yearly?

Sol: Given,

Principal amount (P) = Rs. 62500
Rate (R) = 8%
Time (N) = 3/2 years
Here the interest is calculated half-yearly
So R = R/2 = 8/2 = 4% and 2N = 2 × (3/2) = 3 years
Compound interest = P{1 + [(R/2)/100]}2N
= 62500{[1 + (4/100)]3 – 1}
= 62500{(26/25)3 – 1}
= 62500{[(26)3 – (25)3]/[25]3}
= 62500{(17576 – 15625)/15625}
= 62500(1951/15625)
= [15625 × 4]×(1951/ 15625)
= 4 × 1951
= Rs. 7804
Hence, compound interest is Rs. 7804

What is the compound interest on Rs 6250 at 8% per annum for 1 year if compounded half yearly?

=6760–6250=₹ 510.

In what time will ₹ 6250 amount to ₹ 6632.55 at 4% compound interest payable half yearly?

Detailed Solution For half yearly, rate is halved and time period gets doubled. Calculations: Let the time period be t years. ∴ The required time is 3/2 years.

What would be compound interest of an amount 6250?

6250 at 12% per annum for 1 year, compound half-yearly is. Rs 772.50.