InterviewSolution
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If the difference between the compound interest and simple interest at 17% on a sum of money for 2 years (compounded annually) is Rs. 433.50, then the sum (in Rs.) is:1. 12,0002. 20,0003. 15,0004. 25,000 |
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Answer» Correct Answer - Option 3 : 15,000 Given: Rate of interest = 17% Time = 2 years The difference between CI and SI = Rs. 433.50 Formula used: Simple interest = P × R% × T Calculation: Let the principal be Rs. x. SI = P × R% × T ⇒ SI = x × 17% × 2 ⇒ SI = x × 17/100 × 2 ⇒ SI = 34x/100 ⇒ SI = 0.34x In the case of CI: 1st year CI = P × R% × T ⇒ 1st year CI = x × 17% × 1 ⇒ 1st year CI = 17x/100 ⇒ 1st year CI = 0.17x Amount after 1st year = P + CI ⇒ Amount = x + 0.17x ⇒ Amount = 1.17x 2nd year CI = 1.17x × 17% × 1 ⇒ 2nd year CI = 0.1989x Total CI = 1st year CI + 2nd year CI ⇒ CI = 0.17x + 0.1989x ⇒ CI = 0.3689x Required difference = CI – SI ⇒ 433.50 = 0.3689x – 0.34x ⇒ 433.50 = 0.0289x ⇒ x = 433.50/0.0289 ⇒ x = Rs. 15000 ∴ The sum is Rs. 15000. |
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