Q14

[AndrewL980]

Can someone walk through question 14?

[ohthatpatrick]

Sure thing.

The conditional question adds the constraint that we CAN'T have OS.

We know we always have LM - O - S, by chaining together the 2nd and 3rd rule.

If we can't have OS, then we need to think about what could buffer the O from the S. The only two letters that are left are R and V.

Could we have LM - O - R - S?
Could we have LM - O - V - S?

According to the first rule, we can't have RS, so we would definitely need to use the V to buffer the O from the S.

So for Q14, we know we're looking at
LM - O - VS

R could go 1st, 3rd, or 4th, by slotting it before the LM, after LM, or after O.

(A) impossible, since VS are stuck together.
(B) Sure! L M O R V S obeys all the rules.
(C) impossible since L is always stuck right below M.
(D) impossible, because if R went 2, we'd have no one who could go first (can't break up the LM chunk)
(E) impossible, because if R were 6, then we'd have SR, which is forbidden by the 1st rule.

Hope this helps.

[obobob]

(B) Sure! L M R O V S obeys all the rules.

@ohthatpatrick

Hi, just a quick question, do you mean L M O R V S, not "L M R O V S" since it says: "The R layer is immediately above the O layer (= O R) ? This layering thing is very confusing, so I just want to make sure before I move on.

Thanks!

[ohthatpatrick]

Yikes! Good catch. I was explaining it right (I think), but wrote it wrong.

[EneriaM811]

Hello,
I was wondering if someone can explain why A and E are incorrect?
Can we not have the following diagram for A?
6. O
5. M
4. L
3. R
2. V
1. S

and can we not have the following diagram for E? - which would then also make B correct (which says "The raspberry layer immediately above the orange layer?)
6. R
5. O
4. M
3. L
2. S/V
1. S/V

There has to be something I'm missing, because all of them cannot be correct, but I just can't see it I guess!

Thanks for any help

[ohthatpatrick]

The scenarios you're presenting are breaking rules. For example, this one you gave for (A)

6. O
5. M
4. L
3. R
2. V
1. S

The last rule says "O is above M but below S".
In your scenario, O is above M, but also above S.
So that's why that scenario can't be used.



The one you provided for (E) and (B) was this

6. R
5. O
4. M
3. L
2. S/V
1. S/V

Again, you'd be breaking rule 3, "O is above M but below S".
Again, you have "O above M but also above S"

It looks like you may have just messed up how you interpreted or symbolized rule 3.

Hope this helps.

[AnnaT620]

Hi MP Team

What is the fastest way of approaching this problem? I tried to think of diagrams where OS are not together - but have been sitting here a while. First I came up with LMROVS, which didn't help. Then I tried again, and put together LMORVS, which led me to B. I imagine there is a better way to approach this given the time constraints?

Above you noted that it always has to be VS - where did this inference come from, I'm not sure I follow?

Many thanks!!
Anna