James id obviously flying to Denver and teh seat numbrtf on his flight is 25.
The factors of 100 are: 2*2*5*5.
The only number that is a product of those factors and can divide into 100 is 25. (subject to the other provisions of the question, for which see below.)
Other products are 2, 4 10 and 50
But 2,4 and 10 are less than 11.
And 50 is greater than 49.
Answer: 25