Question #940

[AlexY297]

Hello I'm not sure I understand this problem completely. Then below it says "If V and R are together, it must be true that ..."

Can someone explain this please?

Thank you,
Alex

[Laura Damone]

Hi there! This diagram is a grouping board. The groups are "m" and "t" - let's call them Monday and Tuesday, and in each group there are three slots. This means 3 elements go on Monday and 3 go on Tuesday. The rules tell us that V and W go together, and that if V is on Monday, R is on Tuesday.

The question stem asks us, if V and R go on the same day, which of the following must be true?

Well, if V and R are on the same day, the "V Monday --> R Tuesday" rule can't get triggered because it would split them up. That means the trigger condition, V on Monday, can't be met. V, then, must be on Tuesday. Since V must be with W and R, that fills up Tuesday and forces everybody else to go Monday, providing the correct answer: Y is on Mon.

Hope the helps!