Answer:
b) jane "had already typed" ten pages when her computer "crashed."
c) They "did not know" where to meet because nobody "had told" them.
Step-by-step explanation:
b) First part gives the result of the sentence before her computer crashed which is past perfect. It was in the past when something happened that stopped the first action making it a simple past.
c) Did not know where to meet is simple past, the sentence states the facts. Nobody told him when to meet before the time which is the past making it past perfect.