EDPT flashcards

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

Constant first difference

In a number series, subtracting each term from the next yields the same value every time, so the series is arithmetic and the next term adds that fixed difference.

Constant second difference

When first differences are not constant but their differences are, the series follows a quadratic rule; the next first difference grows by that constant second difference.

Geometric series test

Divide each term by the preceding term. A constant quotient means the series multiplies by a fixed ratio, so the next term equals the last term times that ratio.

Alternating series split

Separate odd-positioned terms from even-positioned terms and analyze each subsequence independently; many series hide two interleaved rules rather than one.

Fibonacci-type rule

Each term equals the sum of the two terms before it, or a fixed multiple of that sum; verify the rule on at least two consecutive triples before applying it.

Prime number series

Some series list consecutive primes or prime-related values, such as 2, 3, 5, 7, 11; recognizing primes quickly prevents wasted difference calculations.

Square and cube series

Terms may be consecutive perfect squares or cubes, sometimes offset by a constant, as in 2, 5, 10, 17, 26 where each term is n squared plus one.

Digit-sum rule

A series may advance by adding the sum of the digits of the current term; test this when differences look erratic but small relative to term size.

Arithmetic word problem setup

Translate the sentence into an equation by assigning a variable to the unknown, expressing all other quantities in terms of it, then solving the single resulting equation.

Work rate formula

If one worker finishes a job in a hours and another in b hours, combined rate is 1/a + 1/b jobs per hour, and combined time is ab/(a+b) hours.

Distance rate time

Distance equals rate times time. For two objects moving toward each other, add their speeds; moving in the same direction, subtract the slower from the faster.

Percent change formula

Percent change equals the difference divided by the original value, multiplied by 100. A rise then an equal-percent fall never returns to the starting value.

Average and sum relation

Sum equals average times count. To find a missing value, compute the required total for all items and subtract the known values from it.

Ratio scaling

A ratio a:b means the quantities are ax and bx for some multiplier x. Set up the total or difference in terms of x to find the multiplier.

Mixture concentration rule

Total solute equals the sum of solute from each component: c1·v1 + c2·v2 = cfinal·(v1+v2). Use this instead of guessing the final percentage.

Part-to-whole analogy

The first pair relates an item to a larger unit it belongs to, such as page to book; the answer must show the same containment direction, not the reverse.

Cause-to-effect analogy

The first term produces or leads to the second. The correct answer preserves the direction of causation rather than swapping cause and result.

Degree analogy

The pair differs only in intensity, as warm relates to hot; the answer must show the same weaker-to-stronger or stronger-to-weaker ordering.

Function analogy

The first term is a tool or object and the second is its purpose, as scalpel relates to cutting; the answer must match tool-to-use, not user-to-tool.

Category and member analogy

The first term names a class and the second a specific instance, as fruit relates to apple; a reversed or sibling relationship is a distractor.

Antonym versus synonym trap

Some pairs are opposites and some are equivalents. Identify which before scanning choices, because both types often appear among the options.

Rotation versus reflection

A rotated figure preserves orientation and handedness; a reflected figure reverses it. Check whether a distinctive asymmetric element has flipped sides.

Element count rule

Count lines, dots, closed regions, or intersections in each figure. Many abstract sequences change one count by a fixed increment per step.

Shading alternation rule

Track whether shaded regions toggle, cycle through a fixed pattern, or stay fixed while position changes; confirm the pattern over three figures.

Position shift rule

A marker may move clockwise one position per frame, or jump a fixed number of positions; count positions rather than judging by eye.

Symmetry axis rule

The number of lines of symmetry may increase or decrease by a constant across the sequence, so count axes in each figure rather than judging overall shape.

Elimination strategy

When the rule is unclear, test each answer choice against every confirmed pattern; the correct option is the only one violating none of them.

Equal weight pacing

Every item is worth the same, so a hard question costs the same as an easy one; skip and return rather than letting one item consume the clock.

Answer sheet discipline

Answers are machine-scored, so an unanswered item scores zero; ensure every item has a marked response even when the solution is uncertain.

Backsolving technique

Substitute answer choices into the problem, starting with the middle value, to find which satisfies all stated conditions without full algebraic solution.

Estimation check

Round values to convenient numbers to bound the answer before computing exactly; this catches misplaced decimals and arithmetic slips quickly.

Unit consistency check

Before computing, convert all quantities to the same unit, such as minutes to hours; mismatched units are the most common source of wrong arithmetic answers.