IB skill practice

Interpret graph degree sums

Use the handshaking lemma to find edge counts or degree totals.

Paper 1, Paper 2 5 marks Difficulty 3

Interpret graph degree sums - exam scenario

A solar installer graph has 10 edges. Use the handshaking lemma to find the sum of all vertex degrees. Enter the requested value and choose the interpretation that matches the result.

Worked practice: result and interpretation

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