Question bank
Pick an answer to see if you're right — with an explanation.
All topicsPythonSQL / MySQLData ScienceNumPyPandasMatplotlibMachine LearningDeep LearningArtificial IntelligenceLarge Language ModelsDjangoAPIsGit & GitHubPower BIExcelStatistics
MatplotlibEasy
In Matplotlib, what does a single `Axes` object represent?
aThe x-axis ruler only
bOne plotting panel with its own x and y axis
cThe entire saved image
dA colour map
Explanation: An Axes is one plot area; the Figure is the whole canvas and Axis is a single x or y ruler.
NumPyEasy
How many bytes does one `float32` value use?
a2
b4
c8
d16
Explanation: float32 is a 32-bit (4-byte) type; float64 uses 8 bytes.
PandasEasy
Which argument makes `pd.read_csv` interpret 05/04/2025 as 5 April 2025?
amonthfirst=False
bdayfirst=True
cformat='US'
dparse_dates=False
Explanation: `dayfirst=True` tells the parser the day comes before the month.
Power BIEasy
A depot file has one column per month (Apr, May, Jun...). Which Power Query transform turns them into `Month` and `Sales` columns?
aPivot Columns
bUnpivot Other Columns
cMerge Queries
dTranspose
Explanation: Unpivot collapses many value columns into an attribute/value pair; Unpivot Other Columns keeps working when a new month arrives.
PythonEasy
What does `sorted([3, 1, 2])` return?
aNone
b[1, 2, 3]
c(1, 2, 3)
dIt sorts in place
Explanation: `sorted()` returns a new list; `list.sort()` is the in-place version that returns None.
SQL / MySQLEasy
Which keyword starts a Common Table Expression?
aWITH
bUSING
cDEFINE
dAS
Explanation: A CTE is introduced with `WITH name AS (...)`.
StatisticsEasy
Which sampling method guarantees every city is represented in proportion to its size?
aConvenience sampling
bSnowball sampling
cStratified sampling
dSelf-selected online survey
Explanation: Stratified sampling draws separately within each group, so no group is missed.
PythonEasy
Which keyword defines a function?
afunc
bfunction
clambda
ddef
Explanation: Functions are defined with `def`; `lambda` creates anonymous functions.
SQL / MySQLEasy
Which JOIN returns all rows from the left table?
aINNER JOIN
bCROSS JOIN
cLEFT JOIN
dRIGHT JOIN
Explanation: LEFT JOIN keeps every row from the left table.
PandasEasy
Select rows by label with…
aloc
biloc
cat
dix
Explanation: `loc` is label-based; `iloc` is position-based.
Machine LearningEasy
Why split data into train and test sets?
aTo evaluate on unseen data
bTo train faster
cTo reduce features
dTo balance classes
Explanation: Test data estimates real-world performance.
DjangoEasy
Django's architecture is often called…
aMTV
bMVC
cMVVM
dMVP
Explanation: Model-Template-View.
Large Language ModelsEasy
RAG stands for…
aRandom Answer Generation
bRecursive Attention Graph
cRapid AI Gateway
dRetrieval-Augmented Generation
Explanation: Retrieve relevant context, then generate.
Artificial IntelligenceEasy
In an expert system, which component decides which rules fire and in what order?
aWorking memory
bInference engine
cKnowledge base
dUser interface
Explanation: The knowledge base stores rules and working memory stores facts; the inference engine applies them.
APIsEasy
Which status code tells a client it is sending too many requests?
a403
b409
c503
d429
Explanation: 429 Too Many Requests is the standard rate-limit response, often with Retry-After.