Unit 14 · Ordering Deduction
Idris & the Four Treasure Boxes — Which Fourth Clue?
Lesson 5 of 6
About this lesson
Idris has four treasure boxes (W, X, Y, Z) and three ordering clues. From them he can work out W > X > Z and W > Y — but Y's position relative to X and Z is still unknown (three possibilities). The question asks which fourth clue would make the ordering unique. The trick is to test each option and see whether it collapses all possibilities to exactly one.
Chapters
Question
Idris is trying to solve a puzzle. He has four boxes labelled W, X, Y, and Z. He knows that there is a different amount of treasure in each box. He has four clues about the boxes (the fourth clue is not shown):
Clue 1: Box X contains more treasure than box Z.
Clue 2: Box W contains more treasure than box Y.
Clue 3: Box W contains more treasure than box X.
After reading all four clues, Idris is able to put the chests in order of how much treasure they contain.
Which one of the following could be the fourth clue?
Take your OC prep further
- Sample questions & worked solutions across core OC topics
- Digital exam simulator with interactive practice sets
- Personalised progress tracking across all your devices
Already have an account? Log in here
No payment required. Compare OC plans
Give Your Child the Best Chance at OC Entry
Join NSW families preparing their children for the Opportunity Class Placement Test with the most realistic online OC practice tests available. First tests free—no credit card required.
Claim Your Free OC Practice Tests