Answer:
1 and 2/3 hours (One hour and 40 minutes.)
Explanation:
Karen has 3 and 1/3 hours.
She spends 1 and 2/3 hours at the store.
3 and 1/3 - 1 and 2/3 = 1 and 2/3 or 5/3 is the time she had left after being at the grocery store.
Because the rest of the time was spent at the library, that is your answer.