The B.G. on a certain sum 4 years hence at 5% is Rs. 200. What is the present worth?

T = 4 years
R = 5%
Banker's Gain, BG = Rs.200

$TD= \frac{BG\times 100}{TR}=\frac{200\times 100}{4\times 5}=Rs.1000$

  $TD=PW\times BG$

$\Rightarrow 1000=PW\times 200$

=>PW = Rs.5000