Gce Model Questions Vol1 2018 Government Question 27

In a country with five single‑member constituencies, the vote shares for parties A, B and C are as follows:\n\nConstituency 1: A 45\%, B 35\%, C 20\%\nConstituency 2: A 30\%, B 40\%, C 30\%\nConstituency 3: A 55\%, B 25\%, C 20\%\nConstituency 4: A 20\%, B 50\%, C 30\%\nConstituency 5: A 25\%, B 45\%, C 30\%\n\nUnder first‑past‑the‑post each constituency elects the party with the highest share. The country also uses a nationwide proportional representation system to allocate ten seats, with a 5\% electoral threshold and the largest‑remainder method. The national vote shares are A 35\%, B 38\%, C 27\%. How many more seats does Party C obtain under proportional representation than under first‑past‑the‑post?