Enabling conditions /Validation functions

I have a categorical multi-select question which asks “select all shocks experienced by household members?” and lists the choices.
Then i have a roster for each of the "selected shocks"asking further associated questions.

  1. What enabling condition can i use so that only the rosters for the selected shocks will appear?

                              Similarly
    

Another numeric question asks “In how many income generating activities has your household engaged in?” Then there is a followup categorical multi-select question that asks “What are the different Income generated activities your household is engaged in?” and lists the choices and a roster asking in detail about each of the IGAs mentioned.

  1. What sort of validation condition shall i use so that the number of IGAs in the first question and those selected in the following do not differ?

2.What enabling condition can i use so that only the rosters for the selected items appear ?
Finally
I have a numeric question that asks for age?

  1. What sort of validation function should i use so that the answer does not have a number more than three digits?

Much appreciated !

Neba,

1-2) the roster buttons only for selected items will appear automatically.
3) think outside the box: 999 is three digits, but you don’t want that as age in years. instead validate age is smaller than 120 or so.

Best, Sergiy