Solution to 8.

8. Karen will go to the gym unless Mary and Ann want to party.

Doing the grouping, we get

(Karen will go to the gym) unless (Mary and Ann want to party).

There are clearly three simple statements at work here:

K = Karen will go to the gym.

M = Mary went to the party.

A = Ann went to the party.

The last two are combines as a compound subject in the original statement, so substituting the letters in we get:

(K) unless (M and A)

Since 'unless' is translates as a disjunction, we get