IB skill practice

Use proof by contraposition

Prove implications by proving the contrapositive statement.

Paper 1, Paper 2 5 marks Difficulty 5

Use proof by contraposition - proof by contraposition item

Case A14. Use the proof-flow diagram and calculate the requested contrapositive code, boundary, or remainder.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.