Hey debtless.

You should show what you have tried and think about it in terms of variables.

To get you started you have three variables here - total amount, amount for boys and amount for girls. Boy and girls amounts are based on number of people and the amount per person.

All up - you have five variables and you have to find some formula that links all of them together in some way.

See if you can go further and tell me how you might try and do that - we can provide assistance if you show your attempts to do so.