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a certain sum is invested at compound interest p.a. the interest accrued in the first three years in rs 1402 and four years in rs 1834 find the rate percentage. |
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Answer» <P>Answer: answr search What would you like to ask? 8th Maths Comparing Quantities Compound Interest A certain sum is interested... MATHS avatar Asked on December 26, 2019 by Shourya Mozhi A certain sum is interested at compound interest . The interest occurred in the first two years is RS. 272 and that in the First three years is Rs. 434. FIND the rate % ? MEDIUM Share Study later ANSWER For first two year interest =P[(1+ 100 R
) 2 −1]=272 .......(1) For first three year interest =P[(1+ 100 R
) 3 −1]=434 .......(2) On dividing EQUATION (1) by (2), we get ⇒ (1+ 100 R
) 3 −1 (1+ 100 R
) 2 −1
= 434 272
Let (1+ 100 R
)=x ...........(3) ⇒ (x 3 −1) (x 2 −1)
= 217 136
⇒ (x 2 +x+1) (x+1)
= 217 136
136x 2 −81x−81=0 After solving x will be 1.1248 By putting this value in eq (3), we get R=12.48 approx 12.50 % |
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