Series – Quick Study Notes for Assam TET
What is a Series?
A series is a list of numbers that follow a clear rule (pattern).
Think of it as a secret recipe: each number is made from the previous one by adding, multiplying, or doing something else.
1. Why Series Matter
| TET Question | What you need to do |
|---|---|
| “Find the next number.” | Spot the rule and apply it. |
| “Write the series.” | Start from a given number and keep applying the rule. |
| “Which of the following is missing?” | Match the rule to the list. |
2. Common Patterns (with everyday analogies)
| Pattern | Everyday Analogy | How it looks in a series |
|---|---|---|
| Addition (or Subtraction) | Adding a new friend each week. | 2, 5, 8, 11, … (add 3) |
| Multiplication (or Division) | Doubling your savings each month. | 3, 6, 12, 24, … (×2) |
| Alternating | Switching between two chores. | 2, 5, 4, 7, 6, 9 … (add 3, then subtract 1) |
| Squares / Cubes | Building blocks that grow in size. | 1, 4, 9, 16, … (1², 2², 3², 4²) |
| Number of letters in words | Counting letters in “one, two, three”. | 3, 3, 5, 4, 4, 3, 5 … |
| Fibonacci‑like | Growing a sunflower seed pattern. | 1, 1, 2, 3, 5, 8, … (add previous two) |
3. How to Crack a Series: Step‑by‑Step
-
Look at the first few numbers.
Example: 4, 7, 10, 13 -
Check simple operations.
- Add/subtract?
4 → 7 (+3), 7 → 10 (+3)… - Multiply/divide?
- Square or cube?
- Alternate?
- Add/subtract?
-
Write the rule.
Rule: “Add 3 each time.” -
Predict the next number.
13 + 3 = 16 -
Double‑check with the last digit of the series.
If the series ends with 8, see if 16 fits the pattern.
4. Quick Tips
| Tip | Why it helps |
|---|---|
| Look for “jump” sizes first. | The biggest leap usually shows the rule. |
| Check parity (odd/even). | Alternating odd/even can reveal a pattern. |
| Use the last digit only if the series is long. | It can show a repeating pattern (e.g., 1, 4, 7, 10 → last digits 1,4,7,0). |
| Don’t over‑think. | Keep the rule simple – most TET questions use basic operations. |
5. Tiny Example
Series: 5, 10, 20, 40, …
- First number: 5
- Each step ×2 (double).
- Next number: 40 × 2 = 80
The rule: “Multiply by 2 each time.”
6. Practice Problem
Series: 3, 7, 11, 15, ?
Your task: Find the missing number.
Think:
- The difference between numbers is 4 each time.
- Add 4 to the last number: 15 + 4 = 19.
7. Final Checklist
- Identify the first few numbers.
- Try addition, subtraction, multiplication, division.
- Look for alternation or repeating digits.
- Write the rule in one sentence.
- Predict the next number and verify.
Good Luck on Assam TET!
Remember: Series = a simple rule + a clear pattern. With a calm mind and a few steps, you’ll crack them in no time.