The ‘110 minus age’ rule suggests how much of a portfolio to invest in equities like stocks or equity funds, with the rest in safer options such as FDs. For a 30-year-old, 110 minus 30 equals 80, meaning 80% in equities and 20% in FDs. In a ₹10 lakh portfolio, ₹8 lakh goes toward growth, while ₹2 lakh ensures stability.