Q20

[esthertan0310]

I ended up with these frames

L M J F G K H
L M J F H G K
M L J F G K H
M L J F H G K

why was the answer "(A) Moreau's session is on the 1st" could not be true?

[fmuirhea]

The final condition: L cannot conduct the session on the 2nd.

Your first two frames are correct: J's being third forces L M to 1 and 2 respectively, and then there's only two options to configure the remaining four elements.

[ohthatpatrick]

Nice response, thanks! I'll put a complete explanation up for posterity's sake.

Rules:
H/M _ _ + M/H
M - J
L - F - GK
L =/= 2

Q20 (Conditional: J = 3)

__ __ J __ __ __ __

What rules pertain to J or spot 3?

M - J. So M is 1 or 2.

(M, __) J __ __ __ __

that means that M is the early half of the M _ _+H rule, so H is after J.
Looking at the L - F - GK rule, we could only fit L in before J, so F - GK are all in the last four spots.

So it looks like we have to have

(M, L) J (F - GK, H)

Oh, but wait! L can't be 2. So the first 3 are set.

L M J (F - GK, H)

Since the question is "could be true" it will likely deal with the last three spots (since those are the ones that still have flexibility)

H has to be at least three after M, so if M is 2 then H's earliest is 5.

The only possible scenarios are
L M J F G K H
or
L M J F H G K

(A) wrong - L is 1st
(B) wrong - K is 6 or 7
(C) wrong - H is 5 or 7
(D) correct - L M J F G K H
(E) wrong - F is 4