📘 AWS Certification – Quantitative Aptitude
Topic: Caselets
1️⃣ What is a Caselet?
A caselet is a short real‑world problem written in words.
Think of it like a mini‑story that hides a math question inside.
You read the story, find the numbers, and then solve for the unknown.
2️⃣ Why Do They Matter?
- They test reading comprehension + math skills at the same time.
- In the AWS exam, they appear in the “Quantitative Aptitude” section.
- They help you practice translating everyday situations into equations.
3️⃣ Types of Caselets (Common Patterns)
| Pattern | Everyday Analogy | What to Look For |
|---|---|---|
| Rate & Work | Two friends cleaning a room together | “time to finish” vs “time to start” |
| Profit & Loss | A shopkeeper sells apples at a discount | “price, cost, profit” |
| Percentage | A student scores 80% in a test | “whole, part, percent” |
| Mixture/Proportion | Mixing paint colors | “ratio of ingredients” |
| Time & Distance | Two cars traveling to a city | “speed, distance, time” |
| Simple & Compound Interest | Money in a savings account | “principal, rate, time” |
(These are the most common types; other variations exist.)
4️⃣ Step‑by‑Step Approach
-
Read Carefully
Stop and underline the numbers that are given.
Ask yourself: “What is being asked?” -
Identify Variables
Give each unknown a simple name (x, y, or a word).
Example: “Let x = number of pens.” -
Draw a Small Diagram or Table
Even a quick sketch helps keep track.
Example: A table with “Item | Quantity | Price | Total”. -
Translate Words into Equations
Use the given relationships.
Example: “Total sold = 120” →x + y = 120. -
Solve the Equations
Use substitution or elimination—whichever is easier. -
Check Your Answer
Plug back into the story. Does it make sense?
Tip: Round only at the end.
5️⃣ Quick Tips (No Jargon)
- Avoid “brain‑filling”: Write everything down.
- Use Everyday Units: If the story talks about “days”, keep “days” in the answer.
- Stay Calm: Take a breath if it feels confusing—often a second look clears it up.
- Practice Regularly: The more caselets you solve, the faster you spot the pattern.
6️⃣ Tiny Example
Story:
A shop sells pens and pencils.
Total sold: 120 items.
Total revenue: ₹240.
Price per pen: ₹1.
Price per pencil: ₹0.50.
Question: How many pens and pencils were sold?
Solution
| Item | Quantity (x) | Price | Total |
|---|---|---|---|
| Pens | x | ₹1 | ₹x |
| Pencils | y | ₹0.50 | ₹0.5y |
| Total | 120 | – | ₹240 |
-
From the story:
Equation 1:x + y = 120(total items)
Equation 2:x + 0.5y = 240(total money) -
Solve:
From Eq1,y = 120 – x.
Substitute in Eq2:
x + 0.5(120 – x) = 240
x + 60 – 0.5x = 240
0.5x + 60 = 240
0.5x = 180
x = 360 -
But 360 pens + 120 pencils = 480 items → Impossible.
Check: Mistake in the money equation: ₹240 is too low for 360 pens.
Re‑check the problem: maybe the revenue is ₹2400, not ₹240.
(In practice, double‑check the statement.)
Lesson: Always double‑check numbers; a typo can make the whole problem unsolvable.
7️⃣ Practice Resources
| Resource | What It Offers |
|---|---|
| AWS Training Portal | Sample caselets from past exams |
| Quantitative Aptitude Books | Chapter on caselets with solutions |
| Online Practice Sites | Timed quizzes on rate, profit, and mixture problems |
| Flashcards | Quick recall of common patterns |
8️⃣ Final Checklist Before the Exam
- Read the whole caselet once without solving.
- Highlight all numbers and words like “total”, “cost”, “time”.
- List unknowns with