Question

Pls show how to solve this

Answer 1

Given:-

Principal = ₹12800

Time = 3 years

Rate = 10% per annum.

To find :-

1. The amount due at the end of the second year.
2. The total interest for the first and the second year.
3. The interest for the third year, if he paid back ₹2000 at the end of second year.

Solution:-

1.) The amount due at the end of second year.

• Principal=₹12,800
• Time = 2years
• Rate = 10%

$\boxed{\sf Amount =Principal \Bigg ( 1 + \dfrac{Rate \%}{100} \Bigg )^t}$

$\sf\implies Amount = 12800 \Bigg ( 1 + \dfrac{10}{100} \Bigg )^2$

$\sf\implies Amount = 12800 \Bigg ( 1 + \dfrac{1}{10} \Bigg )^2$

$\sf\implies Amount = 12800 \Bigg ( \dfrac{10+1 }{10} \Bigg )^2$

$\sf\implies Amount = 12800 \Bigg ( \dfrac{11}{10} \Bigg )^2$

On further solving, we get

$\sf\implies Amount =$₹$\sf 15,488$

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2.) The total interest for the first and the second year.

$\bold{Interest \ for \ 1st \ year,}$

• P = ₹12,800
• R = 10%
• T = 1 year

$\sf Interest = \dfrac{PRT}{100}$

$\sf Interest = \dfrac{12800 \times 10 \times 1}{100}=1,280$

Interest for 1st year = ₹1,280

Amount =Principal + Interest

→₹12,800 + ₹1,280

Amount for 1st year = ₹14,080

____________________________

$\bold{Interest \: for \: 2nd \: year}$

Amount for the 1st year will become the principal for the second year.

• P = ₹14,080
• R = 10%
• T = 1 year

$\sf Interest = \dfrac{PRT}{100}$

$\sf Interest = \dfrac{ 14,080 \times 10 \times 1}{100}=1408$

Therefore,

Total interest of 1st and 2nd year = ₹1,280 + ₹1,408 = ₹2,688

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3.)The interest for the third year, if he paid back ₹2000 at the end of the second year.

Principal for the 3rd year = Amount for 2nd year - ₹2000

= ₹15,488 - ₹2000

= ₹13, 488.

Interest for third year =

• P = ₹13,488
• Rate = 10%
• T = 1

$\sf \implies \dfrac{PRT}{100}$

$\sf \implies \dfrac{13,488 \times 10 \times 1}{100}$

$\sf \implies 1348.8$

Interest for the third year = ₹1348.8

Hope it helps