During a trial, an attorney is planning to call to the stand to testify six different witnesses - T, V, W, X, Y and Z. She will call each witness exactly one time and the order in which she calls them is subject to the following conditions:
The fourth witness must be T.
W and Y must both be called before V.
X must be called before W.
If the attorney calls X immediately after Y and immediately before Z, she must call V

Options

A. first
B. second
C. third
D. Sixth

Answer

D

Explanation

Begin "lt" is used to indicate before because the number of the witness called earlier will be lower than that of a witness called later, e.g., if X is alled first and W is called third, `XltW` because `1 lt 3`. The initial conditions do not determine any particular order, except that T must be fourth.
There is one further conclusion: since `WltV` and `XltW,XltV`. This further conclusion is the basis for the correct answer to Question 21.If you miss this further conclusion, when you get to Question 21, the fact that you don.t find a correct answer will prompt you to return to the initial conditions to look for it and this will consume some precious extra minutes.
The question stem stipulates an order for X, Y and Z: Y-X-Z. There is only one place for three consecutive letters:
`{:("1 2 3 4 5 6"),("Y X Z T "):}`
Next, we reason that W and V must be called fifth and sixth and that W must come before V:
`{:("1 2 3 4 5 6"),("Y X Z T W V"):}`