Total annual drawings (with identical amount at the end of each month) = ₹ 12,000
∴ Monthly drawings =\(\frac{1200}{12}\) = ₹ 1,000,
Now, P = 1000,
R = 12 and N = \(\frac{66}{12}\)
∴ Interest on drawings = I = \(\frac{PRN}{100}\) =1,000 × \(\frac{12}{100}\) × \(\frac{66}{12}\) = ₹ 660