Question

the simple interest on a certain for 8 years at 12 per cent per annun is 3120 more than the simple interest on the same sum for 5 years at 14 per cent per annun. find the sum​

Answer 1

Let Rs. P be the sum

At 12% per annum the interest for 8 years

=

100

P×12×8

=

25

24P

qat 14% per annum the interest for 5 years

=

100

P×14×5

=

10

7P

ACQ,

⇒

25

24P

=3120+

10

7P

⇒(

25

24

−

10

7

)P=3120

⇒(

100

96−70

)P=3120

⇒(

100

26

)P=3120

⇒P=

26

3120×100

⇒P=12000

Answer 2

$\huge \fbox \purple{❥ Answer}$

let the required sum be ' Rs P '

as we know that ,

S.I = P × R × T/100

according to question,

S.I on a sum for 8 years at 12% per annum=Rs 3120 + S.I on the same sum for 5 years at 14 % per annum

P × 12 × 8 /100 = 3120 + P × 14 × 5 / 100

96P /100 = 3120 + 70P / 100

0.96P = 3120 + 0.7P

0.96P - 0.7P = 3120

0.26 P = 3120

P = 3120 / 0.26

P = Rs 12,000

therefore the sum = Rs 12,000

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Your Answer : sum = Rs 12,000

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