I suggest the following model to be followed by 20's.
10% of the earning should be invested in PPF or Pension Policies. Another 10% Should be invested in Nsc or any endowment or money back Plan.
Rest 20% , i suggest should be invested in Mutual Funds as i assume the 20's person is not a share market expert.
The percentage of Equity should be (100- your age) not a global 60 -40 ratio. i.e. if my age is 23, i should invest77% in equities and rest(23%) in debt.