Question 13
Let $M$ be the set of palindromic numbers of the form $5n + 4$, where $n \ge 0$ is an integer. (A positive integer is a *palindromic number* if it remains the same when its digits are reversed. For instance, the numbers 7, 191, 23532, 3770773 are palindromic numbers.)
a) If we write the elements of $M$ in increasing order, which is the 50th number?
b) Among all numbers in $M$, written with nonzero digits who sum up to 2014, which is the greatest one and which the smallest one?
a) If we write the elements of $M$ in increasing order, which is the 50th number?
b) Among all numbers in $M$, written with nonzero digits who sum up to 2014, which is the greatest one and which the smallest one?