### Home > MC1 > Chapter 5 > Lesson 5.1.1 > Problem5-8

5-8.

Thomas Jefferson wrote the Declaration of Independence in a year in which the tens and hundreds digits are equal and the ones and thousands digits have a sum equal to one of the middle digits. The entire digit sum is $21$. In what year was the Declaration of Independence written?

Start with the year $1110$ and increase the second, third, and fourth digits by one until you achieve the correct year.