Find the banker's discount on a bill due 3 years hence at

Find the banker's discount on a bill due 3 years hence at 5% being given that the banker's gain is Rs. 90 ?

T.D. = (90 x 100) / (3 x 5) = Rs. 600
∴ Banker's discount = True discount + Banker's gain
= Rs. 600 + Rs. 90
= Rs. 690