Challenges are randomly selected each day. The type (E.G. earn Positive Morale) is chosen first, and for each type, there is a range for the target. Today's target is to earn 41 positive morale, which was selected from a range for the 'positive morale' challenge. The MilPoints awarded are on a scale, relative to the target... the higher the target, the higher the MilPoints reward.
Hopefully that makes sense...