Find the position of a person from the bottom when the information is given for the position from the top. Do learn the application of the logic used in left to right questions as well.

In these type of questions, you have to study a given number, alphabet series or data related to ranks (position) and answer questions based on that. Usually, the questions are based on finding a particular pattern or finding rank of a particular person.

In this, broadly there are two categories:

**Example 1 :** How many 6s are there in the following number sequence which are

8 6 6 10 5 6 8 7 5 6 10 9 8 6 7 8 7 5 4 3 6 7 8 9

**Solution: ** In this series, you are looking for a group consisting of 6, followed by 7 i.e. 67, which is preceded by 8 i.e. 8 appears before 6. Hence, the complete number becomes 867. Thus in the given series,
8 6 6 10 5 6 8 7 5 6 10 9 867 8 7 5 4 3 6 7 8 9, the required sequence appears **once. **

**Example 2 :** How many even numbers are there in the following series of numbers, each of which is immediately preceded by an odd number, but not immediately followed by an even number?

6 4 5 9 10 8 2 7 6 4 3 10 9 8 4 6

**Solution: ** You are looking for a group of OEO (odd, even, odd) numbers. Thus, in the given series,
6 4 5 9 10 8 2 7 6 4 3109 8 4 6, the required sequence appears only once.

**Example 3 :** If the first half of the given series is reversed, which of the following will be the third digit to the left of the third digit from the right?

6 2 10 4 7 5 3 9 8 2 6 9 9 4

**Solution: ** The series after reversing the first half will look like

3 5 7 4 10 2 6 9 8 2 6 9 9 4

Firstly, count the final position of the digit i.e. third digit to the left of the third digit from the right will be 3 + 3 i.e. 6th digit from right. Now, find the digit at sixth place from the right, which is **8** and hence that becomes your answer.

**2. Ranking Test** The series after reversing the first half will look like

In these type of questions, the rank of a person, both from the top and/ or from the bottom are mentioned and the total number of persons isto be calculated.

**Example 4: ** A class of boys is standing in a single line. One boy is thirteenth from the left hand side as well as from the right hand side. How many boys are there in the class?

**Solution: ** A class of boys is standing in a single line. One boy is thirteenth from the left hand side as well as from the right hand side. How many boys are there in the class?

Let us directly use the formula

**Total number of persons in a row or class = (Rank of a person from upper end or left end) + (Rank of that person from lower or right end) - 1**

**Total number of persons in a row or class = (Rank of a person from upper end or left end) + (Rank of that person from lower or right end) - 1**
So, the total number of boys in the class in this case will be = (13 + 13 –1) = 25.

**Example 5:**
P and Q are ranked sixth and tenth respectively from top in a class of 30 students. What are their respective ranks from the bottom in the class?

**Solution:** Let us use the formula

**Example 6:**
In a class of 32 students, David ranks 6th from the bottom. What is his rank from the top?

**Order & sequencing: Key Learning**

- Rank of a person from lower or right end = (Total number of persons in row) - (Rank of that person from upper or left end) + 1