Question

A ship has sufficient food to supply 600 passengers for 3 weeks. How long would the food last for 800 people??

Answer 1

food=600people x 3weeks
=1800 people.weeks

food = 1800 people.weeks / 800 people
= 2.25 weeks

Answer 2

no,
1800 people.weeks means;
enough food for 1800 people for one week, or
enough food for one person for 1800 weeks,

The food unit (people.weeks) is the amount of food 1 person eats in a week