No problem captain. How much do you charge for advice on tyres?

Now I’m not sure your drilling oil wells is the same? Is there a 1/8 chance of hitting the sweet spot? would you keep going to eight wells if you hit one of the early ones? it wouldn’t be a bad thing if you got more than 1 “hit”.

You’re right, poly – the situation was that someone said that if 1/8 of the spots are sweet, drilling 8 wells would guarantee hitting one, which raised a red flag in my head. It seems to be true that hitting one and only one is the most likely outcome, but it’s far from guaranteed.

Ah, but that’s a slightly different question. The probability of hitting at least one is 66% = 1 – (7/8)^8

Though your scepticism does show that you have a rather better grasp of probability than the person who said that (which to be honest is what I’d expect most people to think).