Exercise 2 solution

(a) Snowy field: average or multi-zone metering tends to underexpose it (the article says by 2 stops or more), so add positive compensation, about +1 to +2 EV as a starting point.
(b) Person in front of a bright window: the bright background can fool the meter into underexposing the person. Spot or partial metering on the person (the article says spot on the subject exposes it correctly, though the bright surroundings overexpose), or positive compensation.
(c) Dark subject filling the frame: the article says a predominantly dark subject often ends up overexposed, so negative compensation.
Exact amounts are starting points, not source values (check).