What century are we living in? In what year did the 15th century begin and in what year did it end?

What century are we living in? In what year did the 15th century begin and in what year did it end? How old will you be (I am 10) in 2040? What century is it? Moscow was founded in 1147. What century is it?

1) Now we live in the 21st century (2019);

2) the 15th century began in 1401 and ended in 1500;

3) If you turned 10 in 2018, then in 2040 you will be 32 years old;

If you turned 10 in 2019, then in 2040 you will be 31 years old;

It will all be in the 21st century (as it is now);

4) Moscow was founded in the 12th century.