A Swedish Timber Mill Produces Planks of Wood

Multiple Choice

A Swedish timber mill produces planks of wood. These are tested and rejected if they are too thick or too thin. If samples of 200 planks are tested and the chance of any single plank being rejected is 2%, what is the mean number of planks in each sample that will be rejected?

A) 2
B) 3
C) 4
D) 5