Analogy, classification and operations: find the rule before the options

Analogy, classification and operations are the standalone reasoning questions — no long arrangement, one or two marks each, and quick if approached in the right order. The single habit that makes them fast is naming the rule before reading the options, because the options are written to tempt a looser rule that fits several of them.

Analogy: name the relationship, then transfer it

An analogy asks you to find the relationship in one pair and apply it to another. The families worth scanning for:

• Meaning: synonym, antonym.
• Structure: part to whole (petal : flower), worker to tool (surgeon : scalpel), cause and effect.
• Category: item to class (sparrow : bird).
• Number relationships: square (4 : 16), cube (3 : 27), consecutive, or a fixed operation.

Fix the relationship in words first — “the second is the workplace of the first” — and only then look at the options. For number analogies, check more than one rule before deciding, since 8 : 64 could be a cube or a square, and the second pair tells you which was intended.

Classification: tighten the rule until one falls out

Odd-one-out questions give four or five items, four of which share a property. The trap is that a loose rule catches several and only a precise rule isolates one:

• If “even number” leaves three candidates, tighten to “multiple of 4” or “not prime”.
• If “city” fits all, tighten to “capital city” or “port city”.

Always look for the most specific shared property. When two options seem odd, your rule is still too broad.

Operations: substitute, then obey BODMAS

Symbol-substitution questions swap the mathematical operators: perhaps + means ×, × means −, − means ÷. The reliable method is two steps, in order:

1. Rewrite the expression with the real operators. Do not try to evaluate and translate at the same time.
2. Apply BODMAS strictly — brackets, orders, division and multiplication, then addition and subtraction — rather than working left to right.

The near-universal error is evaluating in reading order after substitution. The substitution is the easy part; BODMAS is where the mark is won or lost.

A worked reading

“If + means ×, and × means +, find 6 + 2 × 3.” Rewrite: 6 × 2 + 3. By BODMAS the multiplication comes first: 12 + 3 = 15. Evaluated left to right after a careless substitution you would get 8 × 3 = 24 — which is exactly the distractor on offer.

Where the marks leak

Reading options before naming the rule. Decide the relationship or property first; the options are designed to mislead a vague rule.

Stopping at the loosest classification rule. Tighten until exactly one item is excluded.

Left-to-right after operator substitution. Rewrite with real operators, then BODMAS.

Forcing a single number-analogy rule. Verify the rule against the second pair before committing.

Practice that transfers

These reward pattern-recognition speed, which comes from volume on short questions. Work through the analogy, classification and operations practice set, and keep the arithmetic behind number analogies and operations quick with calculation speed.