Order and Ranking
Working out a total from two ranks, converting a rank from one end to the other, counting people between two positions, chaining taller-than and older-than comparisons, and the least-and-most-people questions.
What you will be able to do
- Find the size of a row or list from a person's rank at each end.
- Convert a rank from the top into the matching rank from the bottom.
- Count how many people sit between two given positions.
- Chain comparison statements into one order and read a rank off it.
- Answer 'minimum number of people' questions by overlapping the two groups.
What is inside this lesson
- 1What ranking questions ask
- 2Total from two ranks
- 3Converting a rank from one end to the other
- 4Counting between, and comparison chains
- 5Minimum and maximum people
- 6Worked example
- 7Common mistakes
- 8Quick revision
- 9Practice
Get Pro for full access. This is section 1 of 9; the rest of the lesson opens with Pro at onelystop.in/upgrade.
What ranking questions ask
A ranking question puts people in a single line — a row of seats, a queue, or a merit list from top to bottom — and gives each person's place from one end or the other. You are then asked for the size of the line, someone's place from the other end, the count between two people, or who holds a particular rank.
Every one of these comes down to careful counting, and the single trap running through all of them is whether a particular person is counted once or twice. Draw a short line of dashes and mark positions on it rather than working in your head.
Reading the 9 sections above is free. A free account opens the first 2 topics of every subject in full, along with flashcards and private notes.