Question bank

Pick an answer to see if you're right — with an explanation.

All topics Python SQL / MySQL Data Science NumPy Pandas Matplotlib Machine Learning Deep Learning Artificial Intelligence Large Language Models Django APIs Git & GitHub Power BI Excel Statistics

Data ScienceEasy

What is the main difference between a metric and a KPI?

aA KPI is always a percentage

bA KPI is a metric the business has agreed to steer by

cMetrics come from SQL, KPIs from Excel

dThere is no difference

Data ScienceEasy

Which is a leading indicator for monthly revenue in an online store?

aLast quarter's profit

bAnnual churn rate

cAudited yearly turnover

dItems added to cart this week

Data ScienceEasy

Under India's DPDP Act, 2023, the organisation that decides why and how personal data is processed is the…

aData Fiduciary

bData Principal

cData Processor

dConsent Manager

Data ScienceEasy

Which chart best shows how daily sales changed over six months?

aPie chart

bScatter plot

cLine chart

dRadar chart

Data ScienceMedium

Why should the API call below include `timeout=10`?

resp = requests.get(url, params={"page": 1}, timeout=10)
resp.raise_for_status()

aIt limits the response to 10 records

bIt retries the request 10 times

cIt caches the result for 10 seconds

dIt stops the request waiting forever on an unresponsive server

Data ScienceMedium

Why use a bound parameter like `:start` in `pd.read_sql(text(query), engine, params={...})` instead of an f-string?

aIt prevents SQL injection and handles quoting safely

bIt makes the query run on the GPU

cIt is required for SELECT statements

dIt automatically adds an index

Data ScienceMedium

A chart titled "Sales by month" would be better titled…

a"Figure 1"

b"Monthly sales data (₹)"

c"Sales fell 18% after March in Lucknow"

d"Chart of sales"

Data ScienceMedium

What does this feature-engineering step create?

sales = sales.assign(
    festive=lambda d: d["date"].between("2025-10-01", "2025-11-30")
)

aA string column with the festival name

bA boolean flag marking rows dated in Oct–Nov 2025

cA new DataFrame with only festive rows

dAn error, because assign cannot take lambdas

Data ScienceHard

You SHA-256 hash customer mobile numbers without a salt and share the hashes. Why is this weak protection?

aSHA-256 output is reversible with a decryption key

bHashes are longer than the original numbers

cHashing changes the data type to float

dThe space of 10-digit mobile numbers is small enough to hash every possibility and match

Data ScienceHard

Revenue fell 10% while order count stayed flat. Using a KPI tree (revenue = orders x AOV), where should you investigate first?

aFootfall and app sessions

bConversion rate

cAverage order value: items per order and selling price after discounts

dNumber of stores opened