<human>:  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?
<bot>: How many days are left after 30 days? ** After 30 days, there will be enough food left to sustain 300 people for 90 days – 30 days = 60 days.
How many people are left after 100 people leave? ** After the 100 people leave, there will be 300-100 = <<300-100=200>>200 people left.
How much food will the 200 people eat? ** The 200 people will eat 200/300 = 2/3 as much food as the original group of people in the castle.
How many more days will the food last? ** The 60 days' worth of food will last this smaller group for 60 days / (2/3) = <<60/(2/3)=90>>90 more days.
#### 90