For this must be true question, just look at both of our possible panels. Remember that they are reversible, and we could use one panel twice. Z is the only person who has to be on both panels.
A is wrong because F doesn’t have to be on the panel in both years. G could fill in for F one year instead.
B is wrong. H is only on the panel in one year. It could be the first year, but that panel could also go in the second year (or never). Remember this diagram is reversible.
C is wrong. I doesn’t have to be there if V is there.
D is wrong. We can have a working year without Y, if H is there.
E is CORRECT. Z is always on the panel, no matter who else goes there.
Leave a Reply