Introduction
Puzzles related to ranking and positioning help in developing logical reasoning skills. This section focuses on determining the position of objects or persons in a line or queue.
Explanation Step by Step
To find the total number of people in a row when one person's position is known from both ends, we add the two positions and subtract 1.
Sub-topics
Position in a Queue
This sub-topic covers finding the rank of a person from the front, back, or the total strength of the queue.
Examples
Example 1: Finding Rank from the End
Example 2: Distance between Objects
Tricks and Shortcuts
Total Persons = (Rank from Left + Rank from Right) - 1
Distance between Tree 'A' and Tree 'B' = (B - A) x Gap Distance
Common Mistakes
Counting the number of trees instead of the number of intervals (gaps) when calculating total distance.
Practice Questions
Easy Questions
- In a row of 25 boys, what is the position of the 7th boy from the end?
- Find the distance between the 1st and 6th pole if each pole is 2 meters apart.
- If there are 15 people in a queue, what is the rank of the middle person?
Medium Questions
- In a class of 50 students, Ravi is 18th from the top. What is his rank from the bottom?
- Trees are planted at a distance of 6 meters. What is the distance between the 5th tree and the 14th tree?
- Sita is 12th from the left and 15th from the right in a row. How many people are there in total?
Hard Questions
- In a row of 60 students, A is 15th from the left and B is 20th from the right. How many students are between them?
- A road has 101 poles at equal intervals of 10 meters. What is the total distance from the 10th pole to the 90th pole?
- In a queue, John is 10th from the front and Mary is 25th from the back. If they swap places, John becomes 20th from the front. How many people are in the queue?
Revision Summary
Always remember to subtract 1 when counting the same person twice from both ends, and focus on the intervals for distance problems.