Teacher:In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.
Teacher: Now, understand the problem? Solve this instance: Question: What years was Billy Hughes the prime minister? Passage:Billy Hughes was a former prime minister who had been successively a member of the Labor Party, the National Labor Party, and the Nationalist Party. By 1928, he was the de facto leader of a group of backbenchers hostile to the government of Stanley Bruce (who had replaced him as Nationalist leader in 1923). He and his supporters began to frequently cross the floor and vote against the government, particularly on the controversial subject of industrial relations. On 22 August 1929, Hughes and Edward Mann were expelled from the Nationalist Party for voting in favour of an unsuccessful censure motion against the government. Tensions finally came to a head on 10 September, when Hughes successfully moved an amendment to the government's flagship Maritime Industries Bill. Bruce took this to be a vote of no confidence, and called an election for 12 October. Labor under James Scullin won a landslide victory, while Hughes and two other ex-Nationalists were re-elected as independents.

Student:
Billy Hughes was a former prime minister who had been successively a member of the Labor Party, the National Labor Party, and the Nationalist Party