ABF Officer Recruit Cognify flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Percentage change formula

Percentage change equals (new value − old value) divided by old value, multiplied by 100. A rise from 50 to 60 is a 20 percent increase; a fall back to 50 is a 16.7 percent decrease.

Compound interest formula

Amount A = P(1 + r)^n, where P is the principal, r the decimal interest rate per period and n the number of periods. Interest accrues on accumulated interest, not only on the principal.

Combined work rate

If one worker completes a job in a days and another in b days, their combined rate is 1/a + 1/b, and the time taken working together is ab divided by (a + b).

Speed conversion m/s to km/h

Multiply metres per second by 3.6 to obtain kilometres per hour, and divide kilometres per hour by 3.6 to return to metres per second. Ten metres per second equals 36 km/h.

Divisibility rules 3 and 9

A number is divisible by 3 if its digits sum to a multiple of 3, and by 9 if they sum to a multiple of 9. The digits of 4,731 sum to 15, so it is divisible by 3 but not 9.

All-all syllogism rule

If all A are B and all B are C, then all A are C follows necessarily. The reverse conclusion, that all C are A, is invalid from those same two premises.

Meaning of some in logic

In formal reasoning 'some' means at least one and possibly all; it does not mean 'some but not all'. Conclusions asserting that certain members are excluded are therefore unsupported.

Only if condition meaning

The statement 'A only if B' means A implies B, so B is necessary for A. It does not mean B implies A, so B alone is not sufficient for A.

Inference versus outside knowledge

A valid inference must be supported solely by the passage given. Statements that are true in the real world but absent from the text lie outside the permitted scope of the answer.

Antonym polarity check

Identify the stem word's polarity first: a negative word requires a negative antonym. Then compare the options' charge and intensity before choosing the closest opposite.

Ninety degree clockwise rotation

Rotating a point 90 degrees clockwise about the origin maps (x, y) to (y, −x). A 180-degree rotation maps (x, y) to (−x, −y), preserving shape and size throughout.

Reflection versus rotation

A reflected shape cannot be superimposed on its original by rotation within the plane. Reflection reverses handedness, while rotation preserves the clockwise order of vertices around the outline.

Cube net opposite faces

On a cube net, two faces separated by exactly one face in a straight line become opposite faces when folded. Opposite faces never share an edge on the assembled cube.

Number of cube nets

There are exactly eleven distinct edge-unfoldings, called nets, that fold into a cube. Any candidate net with more than six squares cannot be a cube net.

Feature to track in rotation

During mental rotation, follow one distinctive asymmetric feature such as a notch, dot or marked corner. Symmetric outlines look identical under several rotations and give false matches.

Feature versus conjunction search

Feature search for a single distinctive attribute is fast and largely independent of display size. Conjunction search requiring two combined attributes is slower and demands serial attention.

Inattentional blindness

Inattentional blindness is the failure to notice an unexpected object that is plainly visible, occurring because attention is fully engaged on a different, demanding task.

Change blindness

Change blindness is the failure to detect a change that happens during a blink, eye movement or brief interruption, especially when the change is gradual or unannounced.

Vigilance decrement

Sustained attention declines over time: detection accuracy typically falls after roughly ten to twenty minutes of monotonous monitoring, with missed targets and slower responses becoming more frequent.

Working memory capacity estimate

Modern estimates place working memory at about four chunks, plus or minus one. The older figure of seven plus or minus two reflects immediate serial recall supported by rehearsal.

Chunking definition

Chunking groups separate items into a single meaningful unit, such as digits into a date or a familiar acronym, so that a limited capacity holds more information.

Serial position effect

Items at the beginning and at the end of a list are recalled better than middle items. The recency advantage for final items disappears if recall is delayed.

Proactive interference

Proactive interference occurs when previously learned material disrupts recall of newer similar material, such as an old phone number blocking retrieval of a recently memorised one.

Second difference rule

If first differences between terms are constant, the sequence is arithmetic. If those differences change by a constant amount, the sequence follows a quadratic rule such as n squared.

Alternating sequence rule

When consecutive terms appear unrelated, split the series into odd-positioned and even-positioned terms, then look for a separate rule governing each subsequence.

Fibonacci-type sequence

In a Fibonacci-type sequence each term equals the sum of the two preceding terms, for example 2, 3, 5, 8, 13. The ratio of successive terms approaches 1.618.

Letter position values

Assign A = 1 through Z = 26. Atbash reverses the alphabet, so A becomes Z and B becomes Y; a letter's mirror value is 27 minus its position.

Analogy relation types

Common analogy relations include part to whole, cause to effect, function, degree of intensity and category membership. Name the relation in the given pair before applying it to the new term.

Expected value formula

Expected value is the sum of each outcome multiplied by its probability. A 30 percent chance of winning 100 and a 70 percent chance of 0 gives an expected value of 30.

Sunk cost rule

Sunk costs are past expenditures that cannot be recovered and must be ignored in decisions. Only future costs and future benefits are relevant to the choice being made.

Availability heuristic

The availability heuristic judges probability by how easily examples come to mind, so vivid, recent or heavily reported events are judged more likely than base rates warrant.

Confirmation bias

Confirmation bias is the tendency to seek and weight evidence that supports an existing belief. Countering it requires actively testing evidence that could disprove the hypothesis.