A person can live without food for about a month, but only about a week without water.

and barely a day without air

wrong!!
3 week no food
3 days no water
and 3 mins no oxygen that is how long a human can survive without those needs

Actually, the maximum number of days that one can survive under reasonable temperatures that does not dehydrate the body of essential liquid (well, any temperature above 17 C does), one can expect to survive 20 days without water.