Let's denote the publication year of the first book by x. Then the publication year of the second book is x + 10, the publication year of the third book is x + 20, and so on.
Since the sum of publication years of all ten books is 19,560, we can write the equation:
- x + (x + 10) + (x + 20) + ... + (x + 90) = 19560
Simplifying this equation, we get:
- 10x + (10 + 20 + ... + 90) = 19560
- 10x + 450 = 19560
- 10x = 19110
- x = 1911
Therefore, the first book was published in 1911.