First Round, January 2019

Agatha, Isa and Nick each have a different kind of bike. One of them has an electric bike, one has a racing bike, and one has a mountain bike. The bikes have different colours: green, blue and black. The three owners make two statements each, of which one is true and the other is false: Agatha says: "I have an electric bike. Isa has a blue bike." Isa says: "I have a mountain bike. Nick has an electric bike." * Nick says: "I have a blue bike. The racing bike is black." Exactly one of the following statements is certainly true. Which one? A) Agatha has a green bike. B) Agatha has a mountain bike. C) Isa has a green bike. D) Isa has a mountain bike. E) Nick has an electric bike.