Question

Years at the same rate of interest.
14. A sum of money becomes Rs 6,615 at a compound interest rate of 5% per annum in 2 years. Find
the principal at the beginning of the second year.​

Answer 1

Answer:

the principal at beginning of second yearthe is 661.5

Answer 2

Solution:-

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✺ Here, the question has given us the sum of money that becomes 6,615 at a compound interest rate of 5% per annum in 2 years. Now, the question is asking us to find out the principal at the beginning of the second year. So to find the principal at the beginning of the second year we need to apply the formula of Simple Interest and the last digits will be the principal at the beginning of the second year.

ANSWER:-

✺ The principal at the beginning of the second year will be 6300.

GIVEN:-

↣ Amount after 2 years = Rs 6,615

↣ Rate of interest = 5%

↣ Time = 2 years

TO FIND:-

↣ Principal at the beginning of the second year is = ?

FORMULA:-

✺ First we have to find the principal = A = P[1+(R/100)]^t

SOLVING BY APPLYING THE FORMULA:-

✺ Amount = Rs 6,615

✺ Rate = 5%

✺ Time = 2 years

✺ Principal = A = P[1+(R/100)]^t

⇝6615 = P(1+5/100)²

⇝6615 = P(1+1/20)²

⇝6615 = P(21/20)²

⇝6615 = P × 441/400

⇝P = 6615 × 400/441

⇝P = 15 × 400

⇝P = 6000

So, the principal is Rs 6000.

Principal after 1 year :

⇝6000 + (6000 × 5/100)

⇝6000 + (60 × 5)

⇝6000 + 300

⇝6300

Hence, got our answer. So, the principal at the beginning of the second year will be Rs 6300.

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• S. I = (P × R× T)/100
• Rate = (100 × S.I)/(P × T)
• Amount = P + S.I
• Time = (100 × S.I)/(P × R)
• Principal = 100×Amount/100+(R×T)

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