3.8 Hypotheses, reasons, explanations and inference 111
Which of the following is possible?
A Liam works on Thursday.
B Nadila works on Sunday and
Monday.
C Orla works on Monday and Tuesday.
D Three people work on a Monday.Answers and comments are on pages 319–21.4 The Fitland health centre swimming pool
is open seven days a week. There are
four lifeguards, Liam, Moses, Nadila and
Orla, each working four days a week. None
works four consecutive days and at least
two lifeguards are on duty each day, with
three on duty on Saturday and Sunday.
We know that:
• Liam doesn’t work Monday or Saturday.
• Moses doesn’t work Tuesday, Thursday
or Friday.
• Nadila doesn’t work Wednesday or Friday.
• Orla always works on Thursday.