Question

find compound interest when a sum of Rs. 10,000 is invested for 1 year 3 months at 14% per annum compounded annually.​

Answer 1

Given

• Principal= ₹10,000
• Rate = 14%
• Time = 1 year and 3 months

To Find

• Compound Interest

Solution

For First Year SI

• Principal= ₹ 10,000
• Rate = 14%
• Time = 1 year

$\sf \: SI = \dfrac{p \times r \times t}{100}$

$\sf \: SI = \dfrac{10000 \times 14 \times 1}{100}$

$\sf \: SI = ₹ 1400$

• Amount = Interest + Principle =10000+1400=₹11400.

For second year principle will be amount of previous year (since interest is compounded)

• $\sf ~P~=~₹11400~,~R~=14\%,~$
• $\sf T=3months = \dfrac{3}{12} years =\dfrac{ 1}{4} year's$

$\sf \: SI = \dfrac{p \times r \times t}{100}$

$\sf \: SI = \dfrac{11400 \times 14 \times 1}{100 \times 4}$

$\sf \: SI = \dfrac{160160}{400}$

$\sf \: SI =₹ 400.4$

Total Simple interest = ₹ 1400+400.4= ₹ 1800.4

• ∴Compound interest paid after 1 year and 3months is ₹ 1800.4