Creatively image a question and justification for this answer: 90
The question is: There are enough provisions in a castle to feed 300 people for 90 days. After 30 days, 100 people leave the castle. How many more days are left until all the food runs out?
Step-by-step reasoning process: After 30 days, there will be enough food left to sustain 300 people for 90 days – 30 days = 60 days. After the 100 people leave, there will be 300 - 100 = 200 people left. The 200 people will eat 200 / 300 = 2 / 3 as much food as the original group of people in the castle. The 60 days' worth of food will last this smaller group for 60 days / (2 / 3) = 90 more days.