Answer:
Both mutual funds and money market funds are similar in the sense that they pool money from several investors in a variety of instruments. The difference is that money market funds pool the money in very liquid, short-term securities, while mutual funds do the same but in less liquid, longer-term securities.
The 63-year-old neighbor should therefore split the money around 60/40, 60% of the funds for mutual funds, in order to have long-term security, and 40% in the money market funds, in order to have quick cash available when needed.
