16. Columbus discovered America in the 15th century. In which year did this discovery take place, if the following is known:

a) the sum of the digits representing this year is 16,

b) if the tens digit is divided by the units digit, the quotient is 4 and the remainder is 1.
16. Let $x$ be the number of tens, $y$ be the number of units of the year of discovery. Then: $\left\{\begin{array}{l}x+y=11 \\ x=4 y+1 .\end{array}\right.$ Answer: 1492.