BTGmoderatorDC wrote: ↑

Thu Jul 23, 2020 6:00 pm

A line of people waiting to enter a theater consists of 7 separate and successive groups. The first person in each group purchases one ticket for each person in the group and for no one else. If n is the total number of tickets sold for the first 6 groups, is n an even group?

(1) There are no more than 4 people in each group
(2) The 19th person in line purchases the tickets for the 7th group



OA B

Source: GMAT Prep

We have to figure out the number of ticket sold (thus by logical extension the number of people in the group) ; we have to exclude the 7th group

(1) There are no more than 4 people in each group
6 group * (1 person or 2 person or 3 person or max 4 person)
total people can be 6 to 24
NOT SUFFICIENT \(\Large{\color{red}\chi}\)


(2) The 19th person in line purchases the tickets for the 7th group
The beginning of 7th group is 19, so it means the end of 6th group is 18
18 is even ; so the number of people is even
SUFFICIENT \(\Large{\color{green}\checkmark}\)

Therefore, B