How many children are there between P and Q in a row of children?
I. P is fifteenth from the left in the row.
II. Q is exactly in the middle and there are ten children towards his right.

Options

A. the data in statement I alone are sufficient to answer the question, while the data in statement II alone are not sufficient to answer the question,
B. the data in statement II alone are sufficient to answer the question, while the data in statement I alone are not sufficient to answer the question,
C. the data either in statement I alone or in statement II alone are sufficient to answer the question,
D. the data in both statements I and II together are necessary to answer the question.

Explanation

To solve the problem of how many children are there between P and Q in a row of children, we will analyze the information provided in both statements.

### Step-by-Step Solution:

1. **Understanding the Position of P:**
- From Statement I, we know that P is 15th from the left in the row.
- This means that there are 14 children to the left of P.

2. **Understanding the Position of Q:**
- From Statement II, we learn that Q is exactly in the middle of the row and that there are 10 children towards his right.
- If Q has 10 children to his right, then he must be 11th from the left (since there are 10 children to the right of him).

3. **Determining the Position of P and Q:**
- Now we know:
- P is 15th from the left.
- Q is 11th from the left.

4. **Finding the Number of Children Between P and Q:**
- To find how many children are between P and Q, we can list their positions:
- P is at position 15.
- Q is at position 11.
- The children between them are those in positions 12, 13, and 14.
- Therefore, the number of children between P and Q is:
- 12th (1 child)
- 13th (1 child)
- 14th (1 child)
- This gives us a total of 3 children between P and Q.

### Final Answer:
There are **3 children** between P and Q.