Ah, one of my favourite topics. I've done it here before too
My last thread on the topic was about 100 lots of 100m plus a single 10,000m. I think we concluded Bakele would win that set of races over Bolt.
But this question is very one sided. When I first used to watch Farah, he was actually primarily a 3000m runner. That's where his speed comes from. Here's Farah's 1500m PB:
Personal best(s)
1,500 m: 3:33.98 (Monaco 2009)
To put that 1500m time into context: the Olympic 1500m was
won in 3:34.08. Somehow, I don't think Bolt us going to get anywhere near that!
He doesn't have a recent 800m time. His PB is 1:48, dating from 2003, long before he became the world class athlete he is now. I have no doubt he could beat that time now, probably sustaining a few 52s laps, even. There is no way Bolt could get anywhere close to that either.
The 400m is 50/50 aerobic versus anaerobic. That probably gives it to Bolt. 600m would be 2/3 aerobic to 200m anaerobic. I think even that ratio would mean Bolt would be seriously out of gas long before Farah overtook him,