A question is followed by two statements numbered (I) and (II). You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements carefully and decide the appropriate answer.

Question: 5 people, P, Q, X, Y and Z, have an exam on different days of the same week between Monday and Friday. Who has an exam on Thursday?
Statements:
I. P has an exam on Wednesday. Only one person has an exam between P and Q. Z has an exam immediately before X.
II. No one has an exam between P and Y. Only two people have an exam between Y and X. Z does not have an exam on Monday.

The correct option is: Data in statements I and II together (and not statement I alone or statement II alone) is sufficient to answer the question.

Let us analyze the question and the statements step-by-step to determine who has the exam on Thursday.

The 5 days of the week are Monday, Tuesday, Wednesday, Thursday, and Friday. The 5 people are P, Q, X, Y, and Z.

Step 1: Analyze Statement I alone
According to Statement I:
- P has an exam on Wednesday.
- Only one person has an exam between P and Q. Since P is on Wednesday, Q can have their exam on Monday or Friday.
- Z has an exam immediately before X.

Let's consider the two possible cases for Q:
- Case 1: Q has the exam on Monday.
The remaining available days are Tuesday, Thursday, and Friday. Since Z must be immediately before X, the only consecutive days left are Thursday and Friday. Thus, Z must be on Thursday and X must be on Friday. This leaves Tuesday for Y.
In this case, the schedule is: Monday (Q), Tuesday (Y), Wednesday (P), Thursday (Z), Friday (X). Here, Z has the exam on Thursday.
- Case 2: Q has the exam on Friday.
The remaining available days are Monday, Tuesday, and Thursday. The only consecutive days left are Monday and Tuesday. Thus, Z must be on Monday and X must be on Tuesday. This leaves Thursday for Y.
In this case, the schedule is: Monday (Z), Tuesday (X), Wednesday (P), Thursday (Y), Friday (Q). Here, Y has the exam on Thursday.

Since we have two different possibilities (Z or Y on Thursday), Statement I alone is not sufficient to answer the question.

Step 2: Analyze Statement II alone
According to Statement II:
- No one has an exam between P and Y (which means P and Y are scheduled on adjacent days).
- Only two people have an exam between Y and X.
- Z does not have an exam on Monday.

Let's analyze the positions of Y and X:
- If Y is on Monday, X must be on Thursday (with Tuesday and Wednesday between them).
- If Y is on Tuesday, X must be on Friday (with Wednesday and Thursday between them).
- If Y is on Thursday, X must be on Monday (with Tuesday and Wednesday between them).
- If Y is on Friday, X must be on Tuesday (with Wednesday and Thursday between them).
Without knowing the exact position of P, we cannot uniquely place Y, X, or any other person on Thursday. Thus, Statement II alone is not sufficient to answer the question.

Step 3: Combine Statement I and Statement II
Let us combine the information from both statements:
From Statement I, we had two possible schedules:
- Schedule A: Monday (Q), Tuesday (Y), Wednesday (P), Thursday (Z), Friday (X)
- Schedule B: Monday (Z), Tuesday (X), Wednesday (P), Thursday (Y), Friday (Q)

Now let's apply the conditions of Statement II to these schedules:
- In Schedule A: P (Wednesday) and Y (Tuesday) are adjacent (satisfied). Y (Tuesday) and X (Friday) have exactly two people (P and Z) between them (satisfied). Z is on Thursday, so Z is not on Monday (satisfied). All conditions of Statement II are met.
- In Schedule B: Z is on Monday. However, Statement II explicitly states that Z does not have an exam on Monday. Therefore, Schedule B is eliminated.

With Schedule B eliminated, only Schedule A is valid:
Monday: Q
Tuesday: Y
Wednesday: P
Thursday: Z
Friday: X

We can uniquely determine that Z has the exam on Thursday. Thus, both statements I and II together are necessary and sufficient to answer the question.