Please i need help with this

how do i present "What percent of total household income is from on-farm activities?" in xlsform.
i am trying to input this in the excel sheet
C19 What is your total household income from ALL activities during the last 12 months?
C20 What percent of total household income is from on-farm activities?
C21 What percent of total household income is from farm activities?

Hi @ready

your question is very generic, please provide a sample, maybe attach your xls form.