Three girls – Toni, Alice and Fiona – were sitting near Melissa’s bag when her colouring pencils went missing.

Only one girl is guilty of taking the pencils. When Mrs Hargrieve, their teacher, questions them, they give the following statements:

Toni: “I didn’t take the colouring pencils.”
Fiona: “Alice took the colouring pencils.”
Alice: “I didn’t take the colouring pencils.”

Only one of the three girls is telling the truth; the other two are lying.