<s>[INST] I am a jogger on a metered track where each lap is 400 meters. Unfortunately, the meter markings on the track are currently the result of a prank. Instead of marking every 100 meters as usual, someone has marked non-standard divisions of 120, 150, 200, and other lengths. I can find my 800 meter splits happily with the markings and get more frequent splits from my stopwatch. I can accurately measure distances by taking strolls around the track before and after my jog, so let's assume I can collect some accurate data on the unusual marking lengths, and later use that data to get more precise measurements. However, during my jogs, I'm equally likely to notice and check a marking on the track whether it's an official 100, 200, 400 meter marking or one of the tampered-with markings. If I use the timer and check my time at each marking, but only when I notice it as I'm jogging, I want to know from R what to expect: how often do I notice a marking at my 400 and 800 meter points, and how do I expect to see the time recorded for those markings (assuming I run 2 km total)?[/INST]