Free preview · Lesson 1
Series and Analogies
Letter positions
Keep the alphabet positions handy: A = 1 … Z = 26. A quick trick is EJOTY = 5, 10, 15, 20, 25. The reverse position of a letter is 27 − position (A ↔ Z, B ↔ Y).
Number series checklist
- Differences (and differences of differences)
- Multiplication or division by a fixed or growing number (×2, ×3 … factorial pattern)
- Squares, cubes, primes, n² ± 1
- Two alternating series
Letter series
Convert letters to numbers, find the gap pattern, and convert back.
- A, C, F, J, O, ? → 1, 3, 6, 10, 15 → gaps 2, 3, 4, 5 → next gap 6 → 21 = U.
- Mixed: B2, D4, F8, H16 → letters skip one, numbers double → J32.
Odd one out
Look for the property shared by all but one: perfect cubes (8, 27, 64, 125) vs 100, cities of one state vs another, prime vs composite.
Analogies
State the relationship in one short sentence, then apply it.
- Doctor : Hospital :: Teacher : School (place of work).
- 8 : 64 :: 11 : 121 (square).
- ACE : FHJ — each letter moves +5 — so KMO : PRT.
Tip: if two options both fit loosely, choose the one that matches the relationship most precisely (worker–workplace, tool–action, part–whole).