Hi. If you're using FC-200V calculator, do the following.
Sep 04 2012 02:26 PM
CMPD : Set = End, N=?, I = 10/12, PV = -10,00,000 , PMT = 15,000, FV = 0 and solve. You'll get answer as 97.716 which is in months. If you divide the same by 12, you'll get 8.14 years, which is just over 8 years.
Note: The same calculations can be carried out in Excel sheet, using the formula NPER and feeding the same value, except changing the rate as 10%/12.
Let me know if you still have doubt.