Bill drawn on : 07.05.2011
Tenure : 06 Months
Nominal due date : 07.11.2011
Legally due date : 10.11.2011
Discounted on : 29.08.2011
Unexpired Number of days
August : 02 days
September : 30 days
October : 31 days
November : 10 days
-------------------------------
Total = 73 days
∴n=73365year=15year
Now, Banker's discount, B.D. = Face value - Amount realised
= Rs. 1000 - Rs. 988 = Rs. 12
Using, B.D. =A×n×i, we get
12=1000×15×r100⇒r=12×5×1001000=6%
Hence, the required rate of Interest is 6% per annum.