Reasoning topic
Ranking questions ask where someone stands in a row or a list, or who comes first when people are compared. Write the positions down, and count the person you are placing once.
A typical question gives a position after a move and asks where the person stood before it, counted from the other end. Other questions ask how many are in a row, or who comes first when people are compared.
In a row of 27 students, when Meera was shifted by 2 places towards the left, Meera became 24th from the left end. What was Meera's earlier position from the right end of the row?
2
Moving left lowers her number from the left, so before the move she was 24 + 2 = 26th from the left. From the right, that is 27 + 1 − 26 = 2nd.
Left + right counts the person twice, so total = left + right − 1. The same holds for ranks from the top and the bottom of a list.
To move a position to the other end: from the right = total + 1 − from the left.
For comparisons, write the clues as chains, such as A > B > C, joined wherever one person appears in two clues. If two orders fit every clue and give different answers, the answer cannot be determined.
Putting names in alphabetical order is ranking too: dictionary order decides which name comes first.
In a row of students, Mukesh is 15th from the left and Vibhuti is 15th from the right. If both of them mutually exchange their positions, then Vibhuti becomes 20th from right. Then what is the position of Mukesh from the left in the row?
Answer: 20th
1. In a class, W ranks 57th from the top. V is 5 ranks above W. R is 7 ranks above V. R's rank from the bottom is 25th. How many students are there in the class?
Find R’s rank from the top first. R is in both counts.
69
V is 5 ranks above W: 57 − 5 = 52nd. R is 7 ranks above V: 52 − 7 = 45th from the top.
R is also 25th from the bottom, so the class has 45 + 25 − 1 = 69 students.
2. Among six persons E, F, H, M, N and Z, each has a different height. The height of the third shortest person is 165 cm. Only three persons are taller than E. If N is 20 cm taller than E, then what is the height of N?
Find E’s place counted from the shortest.
185 cm
Three persons are taller than E, so E is 4th tallest. Among six, that is 6 + 1 − 4 = 3rd shortest: the person who is 165 cm tall.
N is 20 cm taller than E: 165 + 20 = 185 cm.
3. Among four persons F, J, P and X, each has a different speed. P runs slower than F. X runs faster than J. Who is the fastest among them?
Is there a person who links the two clues?
Cannot be determined
The clues give F > P and X > J, and no person appears in both.
F > X > J > P fits every clue, and so does X > F > J > P. One puts F first and the other puts X first, so the fastest cannot be determined.
Practise Ranking & Ordering in the app. The questions follow your level, and what you practise comes back just before you'd forget it.
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