Question 20
Two men at points $R$ and $S,$ $76$ miles apart, set out at the same time to walk towards each other. The man at $R$ walks uniformly at $4\dfrac12$ miles per hour; the man at $S$ walks at $3\dfrac14$ miles per hour for the first hour, at $3\dfrac34$ miles per hour for the second hour, and so on, in arithmetic progression. If the men meet $x$ miles nearer $R$ than $S$ in an integral number of hours, then $x$ is: