The apostrophe A Answers
1 Although Tom‘s mother is wealthy she‘s not particularly happy.
2 The examiner‘s worst nightmare came true when he lost his briefcase in a few moments‘ carelessness.
(If you had read ‘they‘ and ‘their‘ in the sentence (instead of he and his) the apostrophe would have been placed in a different position – i.e. "the examiners‘ worst nightmare came true when they lost their briefcase (*) in a few moments‘ carelessness. *We would in any case assume not a communal briefcase but several, so briefcases would be another clue!)
3 I‘m sure the others said we‘ve got an eight o‘clock start tomorrow.
4 Despite having got to bed late, he managed to get up this morning having had a decent night‘s sleep.
5 Mary‘s doctor‘s the best in the city.
6 The day‘s news is on daily at ten in the evening.
7 It‘s time the cat was given its food, isn‘t it?
8 Most farmers in the same situation would‘ve opted to remain on their family‘s land.
9 The documentary‘s on in an hour‘s time.
10 Graham‘s children both support York‘s football and rugby teams.
NB If the sentence read "Mary and Graham’s children both support York’s football and rugby teams" there would still only be one apostrophe, and in the same position after the second name.