Tom, Mary and Jill have apartments in the same building. A s…

Tom, Mary and Jill have apartments in the same building. A security system for their building costs $750. Tom is willing to pay $100 for the security system, Mary is willing to pay $300 and Jill is willing to pay $300. They have a meeting to vote on whether to pay $250 each for the security system. At least two of them must vote for the system to be installed before the vote is passed.