These seem pretty challenging for a 5 year old. I am pretty sure if I was interviewing senior engineers this would stump them - and I would get walk outs: https://i.imgur.com/lRfEQOs.png (from his book).
People who have trouble with that problem have no guts.
If they were hiring cooks / chemists / anyone that is expected to have experience with measuring liquid volumes, it might make sense to assume they have the experience needed to solve this problem.
That sounds bad, but most of them return you to earlier states.
‘Drawing’ a transition graph until you hit a solution in your head can be done in less than a minute. On paper, it shouldn’t take more than 2.
5 - 3 = 2.
3 - 2 = 1.