wawatan wrote:Jane is in a certain ticket line in which each of the other people in the line is either behind her or ahead of her. In the line, the number of people ahead of Jane is 5 more than the number of people behind her. What is the total number of people in the line?
1) There are 11 people ahead of Jane in the line
2) The total number of people in the line is 3 times the number of people behind Jane.
OA will be posted later
THE most powerful rule in data sufficiency is # of equations vs # of unknowns. The more you use this rule, the more time you save.
In the original set up, we have 3 unknowns: the total # of people (let's call it T), the # of people in front of Jane (let's call it F) and the # of people behind Jane (let's all it B).
We also have 2 equations:
T = F + B + 1 (the 1 is Jane)
B = F - 5
So, if we get 1 more equation, we can solve for the entire system.
(1) F = 11... another equation, sufficient!
(2) T = 3B... another equation, sufficient!
Each statement is sufficient on its own, choose (D).
Note that a GREAT test taker wouldn't have bothered to actually translate the equations.
From the original:
1 linear equation with T, F and B
1 linear equation with F and B
3 unknowns
need: 1 more linear equation with no new variables
(1) 1 linear equation with F - good enough
(2) 1 linear equation with T and B - good enough
