Question

a sum of ₹800 becomes ₹956 in 3 years at a certain rate of simple interest.if the rate of interest is increased by 4%, what amount will ₹800 become in 3 years?

₹1020.80
₹1025
₹1052
none of these

explain step by step please
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Answer 1

Answer is ₹1052. See below for explanation

Answer 2

hey mate here is your answer;

P=₹800(in 1 years)

$amount = p \times (1 + \frac{r}{100} ) {}^{n}$

$= > a = 800 \times ( \frac{100 + r}{100} ) {}^{1}$

$= > a = 800 + 8r$

$= > a - 800 = 8r$

$= = > r = \frac{a - 800}{8}$

P=₹956(in 3years)

According to question,

rate=

$( \frac{a - 800}{8} + 4)\%.......(1)$

Now P=₹800,n=3

$a = 800 \times ( \frac{100 + r}{100})$

$= > a = 800 + 8r$

now we know rate from (1) put it as r,

$a = 800 + 8( \frac{a - 800}{100} - 4)$

$= > a = 800 + \frac{8a - 6400}{100} - 32$

$= > a = 768 + \frac{8a - 6400}{100}$

$= > a = \frac{76800 + 8a - 6400}{100}$

$= > 100a - 8a = 76800 - 6400$

$92a = 70400$

$a = 765.217$