Question

Find
the time , in years in
which ₹4,000 will produce
₹630.50 as
compound interest at
5
percent p. a. interest being
compounded annually​

Answer 1

Answer:

3 year and 1 month it take

Answer 2

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☆ 3 years

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☆To find:

• The time

☆Given:

• principal = rupees 4000
• Compound interest =rupees 630.50
• Rate of Percent =5%

☆Formula :

• $ci =p ((1 + \frac{r}{100} ) ^{n} - 1)$
• Ci= compound interest
• p = principal
• r= rate
• n =time

☆Assuming :

• Let the time be n

☆Solution:

ATQ

$630.50 = 4000((1 + \frac{5}{100} ) ^{n} - 1) \\ = > \frac{630.50}{4000} =( (1 + \frac{1}{20} )^{n} - 1 )\\ = > \frac{63050}{400000} =( (\frac{21}{20}) ^{n} - 1) \\ = > \frac{1261}{8000} = ( \frac{21}{20}) ^{n} - 1\\ = > \frac{1261}{8000} + 1 =( \frac{21}{20} ) ^{n} \\ = > \frac{9261}{8000} = (\frac{21}{20} ) ^{n} \\ = > (\frac{21}{20} ) ^{3} = {( \frac{21}{20} )}^{n} \\on \: comparing \\ n = 3$

☆Hence:

• The time is 3 years

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☆Extra information:

• Amount = p(1+r/100)^n
• Simple interest =prt/100
• Amount = principal + interest

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hope it helps.. :)