Who is lying?
Ages 9–12
On an island, every person is a truth-teller, who only says true things, or a liar, who only says false ones. Read what each one says and mark who is which, so no statement is left contradicting itself.
How many islands?
Tap each islander: is she a truth-teller, or a liar? Make every statement hold.
Every island settled
On paper too — Truth-tellers and liars