Need help with networks

[Craxe]

This is from VCAA 2007, exam 2, networks

Can't get it for the life of me - part c, that is. Any help would be greatly appreciated.

[Ilovemathsmeth]

I think you need to follow the route that gives you the most number of children. E.g. 11 children can pass through the middle one starting at West terminal, so you know all 10 can pass there. The same happens until you reach the junction and only 7 can go through. But you know that if you had chosen the path with 9, 9 can get through until a certain point.

I think it's trial and error, but I hope that's helped. I'm not doing networks tomorrow so I'm not really thorough with this module, but that's what it looks like to me, I remember doing this question for a SAC and thinking it was stupid.

[Craxe]

Thats the logic I applied. The answer is 7 though.

But if the children taken the bottom-most route, i.e. the 8, the 9 and then the 10 - can't 8 children get through? Why isn't that route allowed?

[spontaneouscombustion]

10 children set out from West Terminal...that immediately rules out the top route, 9, and the bottom route 8.

[Munis]

because if a train "sets out" from the west terminal with 10, it cannot go through the bottom one (being it has to go through the middle one (being 11), as the train needs to actually "set out from the west terminal"
not a very good question, just need to logically work through it


and yeah someone above answered it as well

[Craxe]

...

That's annoying. Ok, thanks

[lachymm]

Its worded very trickily...