A teacher assigns a team to write a program for the school library that lets students search the catalog, check out and return books, and see any overdue fines. Which plan for decomposing the problem best supports dividing the work among team members and testing each part on its own?

Identify subproblems such as searching the catalog, recording a checkout, recording a return, and computing fines, each with defined inputs and outputs

Have one student write the complete program first, then split the finished code into files of similar length for the others to review

Divide the work by programming construct, with one student writing all the loops, one all the conditionals, and one all the variable declarations

Begin coding the user interface right away and decide on the remaining parts as problems are discovered during testing

Field Value File name IMG_2041.jpg Pixel dimensions 4032 × 3024 Date and time taken Oct 14, 3:42 PM GPS location 40.7128° N, 74.0060° W Device Smartphone camera A teacher plans to post photos that students took of their neighborhoods on a public class website. The table shows information stored inside one of the photo files. Which action best addresses the privacy risk created by the file's metadata?

Remove the GPS location and other identifying metadata from each file before uploading

Reduce the pixel dimensions so that the images load faster

Rename each file with a random number instead of its original name

Convert each image to grayscale before posting

Two students make the same typo, misspelling a variable name on line 20 of their programs. Maria's Python program prints its first three lines of output and then stops with an error message at line 20. Dev's C++ program reports the error before any output appears, and no executable file is produced. Which statement best explains the difference in when the two students discovered their errors?

Python is typically interpreted and executes statements as it reaches them, while C++ is compiled in full before it can run

Python programs are compiled to machine code, so errors are reported only after the output has been printed

C++ programs are interpreted, so the C++ interpreter checks every line before executing the first one

The difference is caused by the IDE each student used, not by how the two languages are translated

A student decomposes a vending-machine program into four procedures: getSelection(), which returns the item code chosen; getPrice(code), which returns that item's price; collectPayment(price), which returns the amount inserted; and makeChange(paid, price), which returns the change owed. Which statement best describes how these components should work together?

The main program should call the procedures in order, passing each one the values it needs and using the values they return

Each procedure should store its result in a global variable that the other procedures read and change directly

The four procedures should be merged into one, because they all depend on the price and cannot be tested separately

makeChange should be written and tested first, because the last step of an algorithm must be designed before the earlier ones

A teacher is creating an online survey about students' study habits to plan homework-help sessions for each grade level. Which data-collection plan best protects student privacy while still meeting the goal?

Collect only grade level and the study-habit responses, without names or ID numbers, and report results only as totals for each grade

Collect full names and home addresses so that follow-up questions can be mailed to students

Collect student ID numbers and birth dates in case the data is useful for a future project

Collect responses with names, but save the file on a shared drive that every student can open so the process is transparent

A middle school class is building an app that shows current weather for their town. Instead of collecting weather data themselves, they use a public weather service's API, following its documentation. Which statement best describes how the API helps the students?

It defines requests their program can send and returns weather data without exposing internals

It supplies the service's source code, which the students import and compile into their app

It gives their program direct read access to the service's database for writing custom queries

It downloads the full weather data set once so the app can run offline without the service

A lab computer suddenly displays a message saying its files have been encrypted and demands payment for the key. Files on the shared network drive the computer uses are also starting to show strange new file extensions. What is the best immediate response?

Disconnect the computer from the network at once and notify district IT to contain the attack

Run a full antivirus scan right away while the computer stays connected to the network

Restart the computer so the malware is cleared from memory before it encrypts more files

Copy the unaffected files from the network drive to a USB drive before taking other steps

NES Computer Science (315)

Free NES Computer Science (315) Practice Questions

10 sample questions for the NES Computer Science (315), with the correct answer and an explanation for each. No account needed. Try each one before you open the answer.

Sections covered on the exam: Computational Thinking and Data Analysis, Programming Concepts, Computing Systems, Networks, and the Internet, Impacts of Computing and Learning Environments.

Question 1 · Computational Thinking and Data Analysis
A teacher assigns a team to write a program for the school library that lets students search the catalog, check out and return books, and see any overdue fines.
Which plan for decomposing the problem best supports dividing the work among team members and testing each part on its own?
- A.Have one student write the complete program first, then split the finished code into files of similar length for the others to review
- B.Identify subproblems such as searching the catalog, recording a checkout, recording a return, and computing fines, each with defined inputs and outputs
- C.Divide the work by programming construct, with one student writing all the loops, one all the conditionals, and one all the variable declarations
- D.Begin coding the user interface right away and decide on the remaining parts as problems are discovered during testing
Show answer and explanation
Answer: B. Identify subproblems such as searching the catalog, recording a checkout, recording a return, and computing fines, each with defined inputs and outputs
Decomposition breaks a problem into meaningful subproblems that each do one job and communicate through clear inputs and outputs, so each can be built and tested separately and then combined. Splitting by programming construct is tempting because it divides the code evenly, but loops and conditionals are not independent tasks and none of the pieces could be tested alone.
Question 2 · Computational Thinking and Data Analysis
Field Value
File name IMG_2041.jpg
Pixel dimensions 4032 × 3024
Date and time taken Oct 14, 3:42 PM
GPS location 40.7128° N, 74.0060° W
Device Smartphone camera
A teacher plans to post photos that students took of their neighborhoods on a public class website. The table shows information stored inside one of the photo files. Which action best addresses the privacy risk created by the file's metadata?
- A.Remove the GPS location and other identifying metadata from each file before uploading
- B.Reduce the pixel dimensions so that the images load faster
- C.Rename each file with a random number instead of its original name
- D.Convert each image to grayscale before posting
Show answer and explanation
Answer: A. Remove the GPS location and other identifying metadata from each file before uploading
Metadata is data about the data; here the embedded GPS coordinates could reveal where a student lives, so it should be stripped before the files are made public. Renaming the files is tempting, but the file name does not hold the location, and the GPS fields remain inside the file after renaming, as they do after resizing or changing colors.
Question 3 · Programming Concepts
PseudocodeFOR i ← 1 TO 3 FOR j ← i TO 3 DISPLAY(i * j) END FOR END FOR
Outputs appear on one line separated by spaces. What is displayed when the nested loops run? (FOR bounds are inclusive.)
- A.1 2 3 4 6 9
- B.1 2 3 2 4 6 3 6 9
- C.1 4 9
- D.1 2 3 4 6
Show answer and explanation
Answer: A. 1 2 3 4 6 9
The inner loop starts at the current i. For i = 1, j runs 1 to 3 and displays 1 2 3. For i = 2, j runs 2 to 3 and displays 4 6. For i = 3, j = 3 and displays 9. The full output is 1 2 3 4 6 9. The nine-number output would come from an inner loop that always starts at 1, which is a full multiplication table.
Question 4 · Programming Concepts
Two students make the same typo, misspelling a variable name on line 20 of their programs. Maria's Python program prints its first three lines of output and then stops with an error message at line 20. Dev's C++ program reports the error before any output appears, and no executable file is produced.
Which statement best explains the difference in when the two students discovered their errors?
- A.Python programs are compiled to machine code, so errors are reported only after the output has been printed
- B.C++ programs are interpreted, so the C++ interpreter checks every line before executing the first one
- C.The difference is caused by the IDE each student used, not by how the two languages are translated
- D.Python is typically interpreted and executes statements as it reaches them, while C++ is compiled in full before it can run
Show answer and explanation
Answer: D. Python is typically interpreted and executes statements as it reaches them, while C++ is compiled in full before it can run
An interpreter translates and executes code statement by statement, so a misspelled name is detected only when execution reaches that line, after earlier output has already appeared. A compiler translates the entire program before producing an executable, so the C++ typo was reported before anything ran. The other options reverse the roles of compiler and interpreter or attribute a language-translation behavior to the editor.
Question 5 · Computing Systems, Networks, and the Internet
Overnight, a malicious program spread to 40 computers on a school network. No one opened an attachment or ran a program; it copied itself from machine to machine by exploiting an unpatched operating system flaw. No files were encrypted and no payment was demanded. Which type of malware is this?
- A.Worm
- B.Virus
- C.Trojan horse
- D.Ransomware
Show answer and explanation
Answer: A. Worm
A worm is self-replicating malware that spreads across a network on its own, often by exploiting unpatched vulnerabilities, with no user action required. A virus also replicates but attaches to a host file or program and spreads when a user runs or opens it, which did not happen here; a trojan relies on a user installing disguised software, and ransomware would have encrypted files and demanded payment.
Question 6 · Computational Thinking and Data Analysis
A student decomposes a vending-machine program into four procedures: getSelection(), which returns the item code chosen; getPrice(code), which returns that item's price; collectPayment(price), which returns the amount inserted; and makeChange(paid, price), which returns the change owed.
Which statement best describes how these components should work together?
- A.Each procedure should store its result in a global variable that the other procedures read and change directly
- B.The main program should call the procedures in order, passing each one the values it needs and using the values they return
- C.The four procedures should be merged into one, because they all depend on the price and cannot be tested separately
- D.makeChange should be written and tested first, because the last step of an algorithm must be designed before the earlier ones
Show answer and explanation
Answer: B. The main program should call the procedures in order, passing each one the values it needs and using the values they return
Well-decomposed components communicate through parameters and return values, so a main program can coordinate them in sequence and each piece can be tested on its own with chosen inputs. Shared global variables are tempting because they avoid passing values, but they let any procedure change data unexpectedly and tie the pieces together so they cannot be tested independently.
Question 7 · Computational Thinking and Data Analysis
A teacher is creating an online survey about students' study habits to plan homework-help sessions for each grade level. Which data-collection plan best protects student privacy while still meeting the goal?
- A.Collect only grade level and the study-habit responses, without names or ID numbers, and report results only as totals for each grade
- B.Collect full names and home addresses so that follow-up questions can be mailed to students
- C.Collect student ID numbers and birth dates in case the data is useful for a future project
- D.Collect responses with names, but save the file on a shared drive that every student can open so the process is transparent
Show answer and explanation
Answer: A. Collect only grade level and the study-habit responses, without names or ID numbers, and report results only as totals for each grade
Privacy-aware collection follows data minimization: gather only what the purpose requires, avoid identifiers when they are not needed, and share results in aggregate. Collecting extra identifiers "in case they are useful later" is a common mistake, because every unnecessary field adds risk if the data is exposed.
Question 8 · Programming Concepts
PseudocodeFOR k ← 2 TO 20 STEP 3 DISPLAY(k) END FOR
In this pseudocode, FOR k ← a TO b STEP s starts at a, adds s after each pass, and runs while k ≤ b. How many numbers does the loop display, and what is the last one?
- A.7 numbers; the last is 20
- B.6 numbers; the last is 17
- C.7 numbers; the last is 23
- D.6 numbers; the last is 20
Show answer and explanation
Answer: A. 7 numbers; the last is 20
k takes the values 2, 5, 8, 11, 14, 17, 20. The next value, 23, exceeds 20, so the loop stops after 7 numbers ending at 20. Dividing the span 18 by the step 3 gives 6, which forgets to count the starting value. The answer ending at 23 displays a value that is already past the bound.
Question 9 · Programming Concepts
A middle school class is building an app that shows current weather for their town. Instead of collecting weather data themselves, they use a public weather service's API, following its documentation.
Which statement best describes how the API helps the students?
- A.It supplies the service's source code, which the students import and compile into their app
- B.It defines requests their program can send and returns weather data without exposing internals
- C.It gives their program direct read access to the service's database for writing custom queries
- D.It downloads the full weather data set once so the app can run offline without the service
Show answer and explanation
Answer: B. It defines requests their program can send and returns weather data without exposing internals
An API specifies the requests a program may send and the form of the responses, such as current conditions as structured data, while hiding how the service works; this is abstraction. Direct database access is tempting because data does come back, but an API exposes only defined operations, not the underlying database. An API also does not hand over source code, and current weather requires calling the service each time rather than a one-time download.
Question 10 · Computing Systems, Networks, and the Internet
A lab computer suddenly displays a message saying its files have been encrypted and demands payment for the key. Files on the shared network drive the computer uses are also starting to show strange new file extensions. What is the best immediate response?
- A.Run a full antivirus scan right away while the computer stays connected to the network
- B.Restart the computer so the malware is cleared from memory before it encrypts more files
- C.Copy the unaffected files from the network drive to a USB drive before taking other steps
- D.Disconnect the computer from the network at once and notify district IT to contain the attack
Show answer and explanation
Answer: D. Disconnect the computer from the network at once and notify district IT to contain the attack
Ransomware is spreading to the shared drive, so isolating the infected machine stops further encryption, and IT can then contain the incident and restore from backups. Copying files first is tempting, but it leaves the infection running and may copy already-encrypted or infected files. A scan while still connected lets encryption continue, and restarting does not remove ransomware, which usually runs again at startup.

Field	Value
File name	IMG_2041.jpg
Pixel dimensions	4032 × 3024
Date and time taken	Oct 14, 3:42 PM
GPS location	40.7128° N, 74.0060° W
Device	Smartphone camera

Keep practicing for the NES Computer Science (315)

TTP Prep has 200 NES Computer Science (315) practice questions with explanations, timed and mock-exam modes, 346 flashcards, interactive lessons, a printable cheat sheet and a readiness score. Start free, no card needed.

Take a free Quick 10 See everything in the NES Computer Science (315) prep