I have problem in mathematics. please i need your help.?

There are 'fixed' expenses and 'daily' expenses...fixed includes the airfare, transport, etc. He's got to spend that money 'off the top' so to speak, so subtract that from the 2500. What's left is divided up per day...so total his daily expenses to see what it's gonna cost per day to eat, sleep, extras, etc and div that into what's left.