Amit lent out Rs. 900 on the condition that the loan is payable in 10 months in 10 equal instalments of Rs. 100 each. Find the rate of interest per annum. ??

• According To Question,
  SI+Principal Amt=10 Months *Rs 100/Month=Rs.1000/-
  Principal Amt.=Rs 900/-
  T=10Months=10/12Years
  Rate=?
  Rate=SI*100/PT
  =Substitute the values in above eqn.
  R=40/3% per annum
  SI=100
  R=PRT
• 9 years agoHelpfull: Yes(0) No(1)
• 100*10=900+((900*10*r)/100*12)
  ==>> r=40/3%
• 8 years agoHelpfull: Yes(0) No(1)
• Amit paid Rs 100 (1000-900) as interest, But he paid it for usage of money for different period ie first Rs100 is paid at the end of 1st month so that 100 is used for only one month,pay 100 x 1/12 x r/100. next month he pay 100 that 100 use for 2 month so pay 100 x 2/12 x r/100 + ....
  ie 100 x 1/12 x r/100 + 100 x 2/12 x r/100 + ....... + 100 x 10/12 x r/100 = 100
  r/12 x 10 x 11/2 = 100
  r = (100 x 2 x 12) / (10 x 11)
  = 21 9/11 %
• 8 years agoHelpfull: Yes(0) No(0)