Rs.1000 is invested at 5% per annum simple interest. if the interest is added to the principal after every 10 years, the amount will become Rs.2000 after :-

• 17 years
  
  At the end of 10 years at 5% per annum simple interest, Rs 1000 will become 1000+1000*10*5/100=1500
  So Rs. 1500 will be again invested for say 'n' years at 5% simple interest to becomes 2000, then
  1500+ (1500*5*n/100)=2000 ,n=20/3=6.66 ~7
  So at the end of 10+7=17 years Rs. 1000 will become Rs. 2000
• 9 years agoHelpfull: Yes(3) No(2)
• At the end of 10 years at 5% per annum simple interest, Rs 1000 will become 1000+1000*10*5/100=1500
  So Rs. 1500 will be again invested for say 'n' years at 5% simple interest to becomes 2000, then
  1500+ (1500*5*n/100)=2000 ,n=20/3=6.66
  So at the end of 10+6YRS 8MONTHS=50/3 years Rs. 1000 will become Rs. 2000
  BUT MONEY OF INTEREST WILL BE ADDED AT THE END OF TEN YEARS. SO, ITS NOT 6YRS 8MONTH BUT 10YS. TOTAL AFTER 20YRS.
• 8 years agoHelpfull: Yes(1) No(1)