The banker's discounted on a sum of money for 1 1/ 2 years is Rs. 60 and the true discount on the same sum for 2 years is Rs. 75. The rate percent is?

B.D. for 3/2 years = Rs. 60
B.D. for 2 years = Rs. (60 x 2) / (3 x 2) = Rs. 80
Now, B.D. = Rs. 80, T.D. = Rs. 75 and Time = 2 years.
∴ Sum = Rs. (80 x 75) / 5 = Rs. 1200
∴ Rs. 80 is S.I. Rs. 1200 for 2 years.
So, rate = (100 x 80) / (1200 x 2)% = 3¹/₃%