Explanation:

Sher Shah Suri was rare monarch in Pre British history, who worked for improving administrative system as against others who simply cared to expand territory or build luxurious buildings. The Mughal tri- metalism coinage system was introduced by Sher Shah Suri.  The term 'rupaya' was used previously for any silver coin.  During reign of Sher Shah Suri, there was standardization of 'rupaya'. The coin was to be of standard weight of 178 grams. Modern rupee is an improvement on the system introduced by Sher Shah Suri. Gold coins were known as 'Mohar', consisting of 169 grains. Copper coins were known as Dam.