A shopkeeper's weighing pan reads 1,050 g when a true 1,000 g weight is placed on it, and it reads high by the same fixed per cent at every load. A packet reads 2,100 g on this pan. What is the packet's true weight?

The pan reads 5% high, so reading = 1.05 $x$ true weight. Hence the true weight = 2100/1.05 = 2,000 g. Check: 2000 + 5% of 2000 = 2100. 1,995 g subtracts 5% of the READING instead of dividing - the wrong base, since the 5% was added on to the true weight, not to the reading. 2,205 g multiplies by 1.05 instead of dividing, and 2,100 g assumes the pan is honest at that load.