Question

Find the compound interest and amount on
(i) Rs 40,000 for 2 years at the interest rate of 8% per annum
(ii) Rs 4,800 for 2 years at the interest rate of 10% per annum​

Answer 1

Solution 1:

$\bf{\underline{\underline{\bf{Given\::}}}}}$

• Principal, (P) = Rs.40000
• Rate, (R) = 8% p.a.
• Time, (n) = 2 years

$\bf{\underline{\underline{\bf{To\:find\::}}}}}$

The compound Interest and amount.

$\bf{\underline{\underline{\bf{Explanation\::}}}}}$

$\longrightarrow\tt{A=P\bigg(1+\dfrac{R}{100} \bigg)^{n} }\\\\\\\longrightarrow\tt{A=40000\bigg(1+\dfrac{8}{100}\bigg)^{2} }\\\\\\\longrightarrow\tt{A=40000\bigg(\dfrac{100+8}{100} \bigg)^{2}} \\\\\\\longrightarrow\tt{A=4\cancel{0000} \times \dfrac{108}{\cancel{100}} \times \dfrac{108}{\cancel{100}} }\\\\\\\longrightarrow\tt{A=Rs.(4\times 108\times 108)}\\\\\\\longrightarrow\tt{\pink{A=Rs.46656}}$

We know that compound Interest,we get;

$\longrightarrow\tt{C.I.=A-P}\\\\\longrightarrow\tt{C.I.=Rs.46656-Rs.40000}\\\\\longrightarrow\tt{\pink{C.I.=Rs.6656}}$

∴ The compound Interest is Rs.6656 and Amount is Rs.46656.

Solution 2:

$\bf{\underline{\underline{\bf{Given\::}}}}}$

• Principal, (P) = Rs.4800
• Rate, (R) = 10% p.a.
• Time, (n) = 2 years

$\bf{\underline{\underline{\bf{To\:find\::}}}}}$

The compound Interest and amount.

$\bf{\underline{\underline{\bf{Explanation\::}}}}}$

$\longrightarrow\tt{A=P\bigg(1+\dfrac{R}{100} \bigg)^{n} }\\\\\\\longrightarrow\tt{A=4800\bigg(1+\dfrac{10}{100}\bigg)^{2} }\\\\\\\longrightarrow\tt{A=4800\bigg(\dfrac{100+10}{100} \bigg)^{2}} \\\\\\\longrightarrow\tt{A=48\cancel{00} \times \dfrac{110}{\cancel{100}} \times \dfrac{110}{100} }\\\\\\\longrightarrow\tt{A=48\times \dfrac{121\cancel{00}}{\cancel{100}} }\\\\\\\longrightarrow\tt{A=Rs.(48\times 121)}\\\\\\\longrightarrow\tt{\pink{A=Rs.5808}}$

We know that compound Interest,we get;

$\longrightarrow\tt{C.I.=A-P}\\\\\longrightarrow\tt{C.I.=Rs.5808-Rs.4800}\\\\\longrightarrow\tt{\pink{C.I.=Rs.1008}}$

∴ The compound Interest is Rs.1008 and Amount is Rs.5808.

Answer 2

$\tt{\huge{\green{Solution_{MV} \::- }}}$

Question :

Find the compound interest and amount on :

Find the compound interest and amount on : (i) Rs 40,000 for 2 years at the interest rate of 8% per annum.

Find the compound interest and amount on : (i) Rs 40,000 for 2 years at the interest rate of 8% per annum.(ii) Rs 4,800 for 2 years at the interest rate of 10% per annum.

Solution :

$\tt{\blue{Formulae \: Used \: :- }}$

$\tt{ \purple{ \leadsto{a = p {( \dfrac{1 + r}{100}) }^{n} }}}$

Substituting the required values and solving :

Part 1 :

A = Rs. 40000

T = 2 years.

R = 8 % per annum .

Substituting the above information in the formula,

We get :

A = 46656

C.I = A - P = 6655

Part 2 :

A = Rs. 4800

T = 2 years.

R = 10 % per annum .

Substituting the above information in the formula,

We get :

A = 5808

C.I = A - P = 1008

__________

Solution :

C.I _(1) = Rs. 6655

C.I._(2) = Rs. 1008.