It’s Split Second with Tom Kennedy from the 1970s.
Now I’ve always *quite* liked Split Second as a show, but my main point of contact was the Monty Hall hosted version, which, if I recall correctly, was shown on the Lifestyle channel on satellite and cable. In it, three contestants quickly buzz in to pick one of three questions to answer on a set of questions on board, with more money being won if fewer people claim correct answers on a set. Quite fun, but let’s be clear here, the real star is the hugely bombastic 80s theme tune.
But the original seventies version has a brilliant twist that the 80s remake removed, and that is you could buzz at any time, even before the actual nature of the question was read out, so it’s not so much a reaction test as it is about question anticipation from incomplete information. Much more interesting!
It looks like Paul Coia hosted a Scottish version in 1987, the logo suggests it was based more on the 80s version than the original.
Buzzr channel in the USA is running repeats of their version at the moment
That 70s twist feels like something that feels much better when it’s an intriguing deliberate format wrinkle (as here) rather than an accidental process of bad question-writing (mid-00s UC was notorious for this, if I remember rightly from Weaver’s Weeks at the time).