To recap: You have a piece of paper and a bunch of blue and red pens. Start with a blue pen and write down all the positive integers in order by spelling them out correctly using the English alphabet: ONE, TWO, THREE, FOUR, etc. Use a red pen the first time you encounter the letter “C”. Assuming that it takes 10 seconds on average to spell out each integer, how long will it be before you need the red pen?

We received over 50 correct responses. The winner is Bradley R. Britton, vice president of investments, UBS Financial Services, in Salt Lake City, Utah. His solution: 

The first positive integer that uses the letter “C” is one octillion, or 1 with 27 zeros. At an average of 10 seconds per integer, it would take 10 octillion seconds, or 317,097,919,837,646,000,000 years. 


Congratulations to Bradley Britton and thanks to all for playing.