manik11 wrote:After an attempted breakout at Folsom State Prison, the warden lines the prisoners up for a headcount. (Assume the warden counts correctly and that no prisoners switch positions or leave/escape during either headcount.) When the warden counts from left to right, Gurby is the 20th prisoner counted, but when the warden counts from right to left, Gus is the 20th prisoner counted. How many prisoners are lined up for the headcount?
(1) There are 13 prisoners between Gurby and Gus.
(2) The total number of prisoners is odd.
Statement 1:
Case 1:
<--19 prisoners--> GURBY <--13 prisoners--> GUS <--19 prisoners-->
In this case
Prisoners to the left of Gurby = 19, with the result that Gurby is the 20th when the count is made from left to right.
Prisoners to the right of Gus = 19, with the result that Gus is the 20th when the count is made from right to left.
Total prisoners = 19 + Gus + 13 + Gurby + 19 = 53.
Case 2:
<--5 prisoners--> GUS <--13 prisoners--> GURBY <--5 prisoners-->
In this case:
Prisoners to the left of Gurby = 5 + Gus + 13 = 19, with the result that Gurby is the 20th when the count is made from left to right.
Prisoners to the right of Gus = 13 + Gurby + 5 = 19, with the result that Gus is the 20th when the count is made from right to left.
Total prisoners= 5 + Gus + 13 + Gurby + 5 = 25.
Since the total number of priosners can be 53 or 25, INSUFFICIENT.
Cases 1 and 2 satisfy both statements.
Thus:
Even when the statements are combined, the total number of prisoners can be 53 or 25, implying that the two statements combined are INSUFFICIENT.
The correct answer is
E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
