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CBSE Class 7 Answered

Respected sir/ma'am, Can you please explain me this question: A sum of money at simple interest doubles itself in 8 years women. In how much time will it triple itself?  
Asked by ranksahoo | 04 Feb, 2018, 09:37: PM
Expert Answer
begin mathsize 16px style Let space the space sum equals Rs. space straight x rightwards double arrow Amount equals Rs. space 2 straight x rightwards double arrow straight S. straight I. equals Rs. space left parenthesis 2 straight x minus straight x right parenthesis equals Rs. space straight x Time equals 8 space years space space months equals 8 4 over 12 space years equals 25 over 3 space years Thus comma space we space have Rate space of space interest equals fraction numerator 100 cross times straight S. straight I. over denominator straight P cross times straight T end fraction equals fraction numerator 100 cross times straight x over denominator straight x end fraction cross times 3 over 25 equals 12 percent sign Now comma Sum equals Rs. space straight x comma space Amount equals Rs. space 3 straight x space and space Rate equals 12 percent sign Then comma space straight S. straight I. equals Rs. space left parenthesis 3 straight x minus straight x right parenthesis equals Rs. space 2 straight x rightwards double arrow Time equals fraction numerator 100 cross times straight S. straight I. over denominator straight P cross times straight R end fraction equals fraction numerator 100 cross times 2 straight x over denominator straight x cross times 12 end fraction equals 50 over 3 space years equals 16 2 over 3 space years equals 16 space years space 8 space months end style
Answered by Rashmi Khot | 05 Feb, 2018, 09:37: AM

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