Queries in Income and Expenditure Section-Visitor Visa

[hrudaya]

I am calling my inlaws to UK from India.They will be paying for their tickets but they will be staying with us. I have doubts in the Employment and income section-

1.What is the cost to you personally of your trip in GBP(£)?-Do we have to write only the amount for the ticket because accommodation and food will be provided by me.Pls help.
2.The total amount of money you have for this trip-Do they have mention only the ticket price?
3.The cost of your living expenses-Is it the expenses in UK or in India?In what currency should they write.
4.Is someone other than you paying for all or a part of your trip?-Does it mean the ticket expenses or it includes ticket + accommodation?
Pls help urgently.