Question 4
a) Let $A=0.1(2453)$ be the recurring decimal $0.1245324532453\ldots$. Find the smallest positive integer $k$ such that $kA$ is an integer.
b) An gives Binh four distinct positive integers and asks for the greatest common divisor of each of the six pairs. The results are $1,2,3,4,5,N$, with $N\gt 5$. Find the smallest possible $N$.
b) An gives Binh four distinct positive integers and asks for the greatest common divisor of each of the six pairs. The results are $1,2,3,4,5,N$, with $N\gt 5$. Find the smallest possible $N$.