What idea does Candy propose to George and Lennie? What reasons does Candy put forward as to why he can help George and Lennie?

Lennie asks George to tell him "about the rabbits," and George launches into his monologue about their proposed self-sustaining farm - complete with rabbits, pigs, cats and a vegetable garden. Candy, who has been listening in, asks how much such a place would cost. George, though put off at first by Candy's nosiness, eventually lets on that he has a lead on a plot of land that could be bought for six hundred dollars. Candy reveals that he has a secret stash of money - three-hundred and fifty dollars - and offers to give it all to George and Lennie if they'll let him live on their farm and work as a housekeeper.