6.1 Data Sufficiency: The CRE Two-Clue Format
Key Takeaways
The CRE Data Sufficiency Test has 8 questions in which candidates choose the combination of TWO numbered clues that solves a problem, from five pair options labelled A to E.
In the CSB sample, the stem fact that only the winner finished in 10 minutes acts as a hidden anchor, so clues (1) and (4) identify Jordan as the winner at 16 minus 6 minutes.
Anchor clues give a fixed value, link clues give a relationship between two items, and a pair usually works only when a link connects an anchor to the item the question asks about.
A pair is sufficient only when it leaves exactly one possible answer; a pair that ranks some candidates but leaves another unconstrained is insufficient.
Testing only the five offered pairs is faster than examining all ten possible pairs of five clues.
6.1 Data Sufficiency: The CRE Two-Clue Format
Quick Answer: Each CRE Data Sufficiency question gives a short problem, a numbered list of clues and five answer options. Each option is a pair of clues, such as "(1) and (4)". You choose the one pair that, together with the facts in the question, gives a single definite answer. The Aptitude Test has 8 of these questions. You are judging whether information is enough, not doing long calculations.
How this format differs from other data sufficiency tests
Some overseas admissions tests use a fixed five-way choice: statement (1) alone, statement (2) alone, both together, either alone, or neither. The CRE does not. The CSB's directions say: "In this test, you are required to choose a combination of clues to solve a problem." Material written for those other tests trains the wrong habit. CRE candidates must compare several clue pairs and find the one that settles the question.
The official sample, step by step
The CSB's sample question:
John, Jack, Joseph and Jordan participated in a running race. Only the winner finished the race in 10 minutes. Which TWO pieces of information can tell you who the winner was?
(1) John finished the race in 16 minutes. (2) Joseph finished the race earlier than Jack by 2 minutes. (3) Jack finished the race later than Jordan by 4 minutes. (4) Jordan finished the race earlier than John by 6 minutes. (5) John finished the race later than Joseph by 4 minutes.
Options: A (1) and (2); B (1) and (4); C (2) and (3); D (2) and (5); E (3) and (4). Answer: B.
The key fact sits in the question itself: only the winner took 10 minutes. Any pair that gives a runner a time of exactly 10 minutes therefore names the winner.
| Option | What the pair tells you | Single answer? |
|---|---|---|
| (1) and (2) | John 16 min; Joseph is 2 min ahead of Jack | No: Joseph and Jack have no fixed time, and Jordan is unknown |
| (1) and (4) | John 16 min; Jordan 6 min ahead of John, so Jordan 10 min | Yes: Jordan is the winner |
| (2) and (3) | Joseph = Jack minus 2; Jordan = Jack minus 4 | No: Jordan beats Jack and Joseph, but John could still be the winner |
| (2) and (5) | Joseph = Jack minus 2; John = Joseph plus 4 | No: Joseph beats Jack and John, but Jordan is unknown |
| (3) and (4) | Jordan = Jack minus 4; Jordan = John minus 6 | No: Jordan beats Jack and John, but Joseph is unknown |
Notice the pattern. Options C, D and E each rank three runners correctly, yet still fail, because the fourth runner is left free. That trap appears again and again.
Anatomy of a CRE data sufficiency item
- Setting: the people, objects or quantities involved (four runners).
- Stem facts: conditions that always apply ("only the winner finished in 10 minutes"). These often act as a hidden anchor.
- Target: the exact thing to identify, which may be a person ("who won"), a value ("how much"), a position ("which floor") or a time ("which year").
- Clues: usually five numbered statements, some useful and some decoys.
- Options: five pairs. Only five of the ten possible pairs of five clues are offered, so you never need to test every combination.
Tagging the clues
Before testing pairs, give each clue a quick tag in the margin:
| Tag | Meaning | Example from the sample |
|---|---|---|
| A (anchor) | Fixes an absolute value for one item | (1) John 16 min |
| L (link) | Relates two items without fixing either | (4) Jordan = John minus 6 |
| S (stem anchor) | A fixed fact stated in the question | Winner = 10 min |
| Decoy | A link between items that never reach the anchor or the target | (2) Joseph and Jack, used with (1) |
Most sufficient pairs combine an anchor with a link that reaches the target, or two links that close a chain to a stem anchor. A pair of two anchors works only if the anchors themselves answer the question.
The four-step method
- Write the target in one line. For example: "Who finished in 10 min?" or "Price of one chair = ?".
- Tag every clue as A, L or decoy, noting which items each one mentions.
- Test the five offered pairs in order. For each, ask: "Is every item that could be the answer either fixed or ruled out?" If one candidate is left free, the pair fails.
- Confirm before marking. When a pair seems to work, check that no alternative arrangement satisfies it. If time permits, confirm that the other pairs fail. Only one pair should be keyed.
Tip
When the target is a person or position, draw a quick number line or ranking ladder. Put anchors on the line first, then hang linked items off them. Any item still floating off the line is the reason a pair fails.
Reading signals in the stem
| Stem wording | What it gives you |
|---|---|
| "Only the winner..." / "Only the tallest..." | A threshold that identifies the answer once any item reaches it |
| "Each joined in a different year between 2018 and 2022" | A closed set of values: no gaps or repeats are allowed |
| "Different whole numbers" | Rules out fractions and ties, which can make a range unique |
| "Which TWO pieces of information..." | Exactly two clues; never assume a third |
Common item settings
The CSB publishes one sample, so these settings are practice categories rather than an official list. Questions built on the same logic include:
- Races and queues: finishing times or positions, with "earlier than" and "later than" links.
- Ages and years of service: "older than by 3 years", "joined two years before".
- Prices and quantities: unit prices, totals and numbers of items.
- Heights, floors and distances: "taller by", "two floors above".
- Schedules: days of the week or years, with one event per slot.
In every setting the same rule applies: count the items that could still be the answer after using the pair. If more than one remains, the pair is not sufficient.
Five officers, Ho, Ip, Ko, Lam and Mo, joined a department in five different years from 2018 to 2022, one officer per year. Which TWO pieces of information can tell you who joined in 2020?
(1) Lam joined in 2022. (2) Ho joined two years before Lam. (3) Ip joined the year after Mo. (4) Ko joined in 2018. (5) Mo joined the year before Lam.
(1) and (3)
(2) and (5)
(1) and (2)
(3) and (4)
(4) and (5)
A stationery shop sells one type of notebook at a fixed price. How much did Wong pay for her notebooks?
(1) Chan bought 4 notebooks and paid $48. (2) Wong bought 3 more notebooks than Lee. (3) Wong bought 5 notebooks. (4) Lee paid $24. (5) Each notebook costs more than $10.
(2) and (4)
(1) and (4)
(3) and (5)
(1) and (3)
(2) and (3)
Five buildings, A, B, C, D and E, have different heights. Only the tallest building is more than 200 metres high. Which TWO pieces of information can tell you which building is the tallest?
(1) Building B is 180 metres high. (2) Building D is 30 metres taller than Building B. (3) Building A is shorter than Building C. (4) Building E is 20 metres shorter than Building A. (5) Building C is 150 metres high.
(1) and (5)
(3) and (5)
(2) and (4)
(4) and (5)
(1) and (2)
Sections you finish are checked off in the contents.