I also do believe that the scoring-riddle is unsolvable without the scores of Mary, Lisa and Dan,
(which to admit took me about three accumulated hours, spent with different approaches,) as long as guessing isn't an option. This way, I can only tell the maximum difference in scoring between each of them.
and that there are four answers they have in common, so between 0-40 points as an lower limitation.
I assume by large intersection you mean one with multiple lanes, warlko? So only two lanes crossing each other? And they all are driving straight forward , no meddling with the steering wheel?
There is an series of 100 numbered lamps, standing in line, and a 100 frogs.
When the lamps are touched they go off (if they were on) and vice versa.
At first, all lights are off.
The first frog jumps on every lamp and switches them on.
The second frog jumps on every second lamp and switches it off (so lamp nr. 2,4,6,... are now off).
The third frog jumps on every third lamp and switches it off/on (depending on its previous state).
And so on.Which lamps remain on after all 100 frogs had their turn?
(And as a bonus question, if there was an infinite series of lamps and an infinite supply of frogs, how could the set of shining lamps be characterized?