There are 17 railway stations in a railway track between A and B. The train stops at 4 intermediate stations at random. Then the probability that at least two of these 4 stations are consecutive is p, then the value of 340p is_____

(197) Train is to be stopped at 4 stations out of 17
Probability (At least two of the 4 stops are adjacent)
= 1 – probability (No two of them are adjacent)
 $=1-\frac{{ }^{n-r+1}{C}_r}{{ }^n{C}_r}wheren=17,r=14=1-\frac{{ }^{14}{C}_4}{{ }^{17}{C}_4}=1-\frac{\mathrm{14.13.12.11}}{\mathrm{17.16.15.14}}=1-\frac{143}{340}=\frac{197}{340}$