Suppose that each number from 1 to 10,000,000,000 written in English and then alphabetically arranged (as in a dictionary) while ignoring spaces and hyphens. What would be the first odd number in the list?
This kind of problem should be solved step by step. You have to take into account the successive words that described the number. First, determine the digit that would appear first in a dictionary. Upon some thought, you can easily figure out that it’s “eight”. Now, think of the next earliest available word that follows “eight”. The earliest word is “billion”. So, the answer is eight billion something…
Following the same logic, you can determine the answer: 8,018,018,885 (eight billion eighteen million eighteen thousand eight hundred eighty-five ).
This odd problem is based on the problem posted by computer scientist Donald Knuth. His problem was: “What is the first prime number in the dictionary?” The way to solve this puzzle is similar to the method outlined above. After some checking on a computer, you would eventually get the answer: 8,018,018,851.