Question

A sum of money put at 9% per annum simple interest amounts to ₹10160 in 3 years. What will it amount to in 2 years at 8% per annum​

Answer 1

i hope its answer is right

Answer 2

Explanation -:

Given :

• Amount = ₹10160
• Rate = 9% p.a.
• Time = 3 years

To Find :

• Amount in 2 years at 8% per annum

Solution :

Let us assume the principal as 'x'

$\star \: \small \fbox{\rm{SI = Amount - Principal}}$

$\small \sf{SI = ₹(10160 - x) }$

$\star \: \small \boxed {\rm{SI = \dfrac{P × R × T}{100}}}$

$\small\sf{10160 - x = \dfrac{x \times 9 \times 3}{100} }$

$⇢ \small\rm{ - x + 10160 = \dfrac{x \times 9 \times 3}{100} }$

$⇢\small\rm{ - x + 10160 = \dfrac{27}{100} }$

$⇢ \small\rm{ - x = \dfrac{27}{100} - 10160 }$

$⇢ \small\rm{ - 100x = 27x - 1016000}$

$⇢\small\rm{ - 100x + 27x = - 1016000}$

$⇢ \small\rm{127x = 1016000}$

$⇢ \small\rm{ x = \dfrac{ \cancel{1016000}}{ \cancel{127}} }$

$⇢ \small\rm{x = 8000}$

Principal = ₹8000

Finding the Simple Interest for 2 years at the rate of 8% per annum

Principal = ₹8000

Rate = 8% p.a.

Time = 2 years

$\star \: \small \boxed{\rm{SI = \dfrac{P× R × T}{100}}}$

$\small\sf{SI = \dfrac{80 \cancel{00} \times 8 \times 2}{1 \cancel{00}}}$

$⇢\small \rm{SI =80 \times 8 \times 2 }$

$⇢ \small\rm{SI = 1280}$

Finding the Amount for 2 years

$\star \: \small \boxed{\rm{ Amount = Principal - Interest}}$

$\small\rm{Amount = 8000 + 1280 = 9280}$

Amount = ₹9280

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NOTE :

• P stand for Principal
• SI stand for Simple Interest
• T stand for Time
• R stand for Rate
• A stand for Amount