Convert from drum [metric, petroleum] to cup [metric]

Unit Definition (drum [metric, petroleum])
The drum [metric, petroleum] is a unit of volume sometimes used in the oil trade. In the metric world, drums of 200 liters, 205 liters, and 208 liters are in use as substitutes for the traditional size.

Unit Definition (cup [metric])
The cup [metric] is an informal metric unit of volume equal to 250 milliliters, commonly used in recipes in Australia.