The banker's discount on a bill due 6 months hence at 6% is Rs. 18.54. What is the true discount?

T= 6 months = 1/2 year
R = 6%
$TD= \frac{BD\times 100}{100+TR}=\frac{18.54\times 100}{100+\frac{1}{2}\times 6}=Rs.18$