compound interest on a sum for 2 years is 7560 for 2 years at the rate of 10%. find the simple interest on the sum.

• Total Compound interest = 121/100 - 1 = 21/100 * SUM
  Simple interest = 20/100 * SUM
  So , Simple interest = (7560/21 ) * 20 = 7200 (ans)
• 9 years agoHelpfull: Yes(0) No(1)
• 7200/- in one year 3600 and second year 3600
  short trick
  devide 7560 in three part showing below and evey part should be 10%
  
  1st year ...3600..
  2nd year ...3600..+ ...360.....
  so 1st year and second year first part is simple intrest so 3600+3600=7200
• 9 years agoHelpfull: Yes(0) No(2)
• how it is 7200?can anyone explain?
• 9 years agoHelpfull: Yes(0) No(0)
• we know that
  C.I= A-P and A=p*(1+r/100)^n
  
  so that C.I= p*(1+r/100)^n -P
  
  take a p as common and it becomes
  
  C.I= P [(1+10/100)^n - 1]
  
  =P[[110/100]^2 - 1]
  
  = P[[11/10]^2 -1]
  
  =P[[121/100 - 1]
  C.I = P [21/100]
  and C.I=7560
  solve P and get the answer..
  
  
  
• 9 years agoHelpfull: Yes(0) No(0)