Short answers, pulled from the story.
Germany introduced the Reichsmark in 1924 to replace the Papiermark following a period of hyperinflation that peaked in 1923. The exchange rate between the old Papiermark and the new Reichsmark was set at one trillion Papiermarks for every single Reichsmark.
Inflation reduced the value of the Reichsmark from four Reichmarks per dollar at the start of the war to two thousand Reichmarks per dollar by its end. A barter economy emerged as citizens exchanged goods directly when money lost all purchasing power after V-E Day.
The Deutsche Mark replaced the Reichsmark in the Trizone on the 21st of June 1948 at a rate of ten to one. Cash and current accounts converted at a one-to-one ratio instead, while this new currency also replaced the Reichsmark in the three Western sectors of Berlin three days later.
Wartime shortages forced changes in coin materials from bronze to zinc and aluminum between 1940 and 1945. The 10 Reichspfennig coin minted entirely of zinc replaced the earlier aluminium-bronze version with its golden color.
From 1942 to 1943, tokens struck for use within the Łódź Ghetto circulated among prisoners. Military Reichsmark currency was also issued for use by the Wehrmacht from 1942 to 1944.