Dr. T’s problem

This logic problem involves two activities exploring what initially appear to be conflicting statements. In the first problem, a teacher draws horses on a sheet of paper and holds the sheet up to the class, asking ‘how many horses do you see altogether’. One student replies ‘three’ and is told correct, the second student replies ‘four’ and is told ‘correct’. The challenge is to work out how many horses the teacher actually drew.

The second challenge involves three sentences that reference themselves as being either true or false. The challenge is to establish which of the statements are actually true (or false).