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Grade 11 Challenge: Algorithms & Real Computing Worksheet with Answers

Grade 11 (US) · Year 12 (UK) · Class 11 (India) · Computer Science

Unit 5: Going FurtherReal-World ChallengeChallenge

Computing as engineers meet it: password-cracking time, binary search on billions, subnets, two's complement and Python surprises. This free high school worksheet has 12 questions and a full answer key. Print it or save it as a PDF — every answer is checked by code, not guessed.

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Challenge: Algorithms & Real Computing

Grade 11 · Computer Science

Score___ / 12

Name

Class

Date

Learning goal: Real-World Challenge

Directions: Read each question carefully and write your answer on the line.

Example

Tower of Hanoi with 18 disks: what is the fewest moves needed to move the whole tower?

Answer: 262143

  1. 1

    The byte 10101011 is a signed 8-bit integer in two's complement. What decimal value does it hold?

  2. 2

    A network is given the IPv4 block /27. How many usable host addresses does it have? (Two addresses are reserved.)

  3. 3

    Tower of Hanoi with 17 disks: what is the fewest moves needed to move the whole tower?

  4. 4

    An O(n²) sorting algorithm takes 5 seconds for 10 000 items. Roughly how many seconds will it take for 10 000 000 items?

  5. 5

    In Python, what does print(-3 % -2) show? (the result takes the sign of the divisor)

  6. 6

    An attacker can try 1 million passwords per second. A password is 8 lowercase letters (26 options each). How many hours to try every possibility? Give 1 decimal place.

  7. 7

    Tower of Hanoi with 9 disks: what is the fewest moves needed to move the whole tower?

  8. 8

    In Python, what does print(11 % -2) show? (the result takes the sign of the divisor)

  9. 9

    Binary search is used on 1 000 sorted names. In the worst case, how many items must it check?

  10. 10

    A network is given the IPv4 block /22. How many usable host addresses does it have? (Two addresses are reserved.)

  11. 11

    What is the fewest bits needed to give each of 1 000 products its own unique binary ID?

  12. 12

    The byte 11100000 is a signed 8-bit integer in two's complement. What decimal value does it hold?

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Teacher's comments

Free printable worksheets with answer keys · aethelsystems.com/worksheets/computer/11/challenge_cs_senior

Answer key (click to show)
  1. 1.-85
  2. 2.30
  3. 3.131071
  4. 4.5000000
  5. 5.-1
  6. 6.58.0
  7. 7.511
  8. 8.-1
  9. 9.10
  10. 10.1022
  11. 11.10
  12. 12.-32

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