Where would you look learn whether Mark Twain born before or after jules verne?

Both authors can be looked up (separately) on google, and you can easily find their dates of birth. I looked it up for you. Mark Twain was born on November 30, 1835, and Jules Verne was born on February 8, 1828. Therefore, Verne was born about 7 years before Twain.

If you are looking for the answer regarding where you would have looked for this information in the past, you likely would have found the answer in the Dictionary of American Biography.