Naneen and Praveen borrowed 42000 and 55000 respectively for 7/2 years at thes same rate of interest. If Praveen has to pay 3640 more than Naveen , Find the rate of interest.
 
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Asked by Rishi | 11th Oct, 2015, 02:55: PM

Expert Answer:

L e t space apostrophe r apostrophe space b e space t h e space r a t e space o f space i n t e r e s t. G i v e n space t h a t space N a v e e n space b o r r o w e d space R s.42000 space a n d space P r a v e e n space b o r r o w e d space R s.55000. T i m e space p e r i o d equals 7 over 2 space y e a r s S. I space p a i d space b y space N a v e e n equals fraction numerator 42000 cross times r cross times 7 over denominator 2 cross times 100 end fraction S. I space p a i d space b y space P r a v e e n equals fraction numerator 55000 cross times r cross times 7 over denominator 2 cross times 100 end fraction D i f f e r e n c e space i n space t h e space i n t e r e s t s space p a i d space b y space P r a v e e n space a n d space N a v e e n equals R s.3640 rightwards double arrow fraction numerator 55000 cross times r cross times 7 over denominator 2 cross times 100 end fraction minus fraction numerator 42000 cross times r cross times 7 over denominator 2 cross times 100 end fraction equals 3640 rightwards double arrow fraction numerator 550 cross times r cross times 7 over denominator 2 end fraction minus fraction numerator 420 cross times r cross times 7 over denominator 2 end fraction equals 3640 rightwards double arrow 550 cross times r cross times 7 minus 420 cross times r cross times 7 equals 2 cross times 3640 rightwards double arrow 7 r open parentheses 550 minus 420 close parentheses equals 7280 rightwards double arrow 7 r cross times 130 equals 7280 rightwards double arrow 7 r equals 7280 over 130 rightwards double arrow 7 r equals 56 rightwards double arrow r equals 56 over 7 rightwards double arrow r equals 8 percent sign

Answered by Vimala Ramamurthy | 12th Oct, 2015, 10:38: AM

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