AP CSP Digital Information Review

What is the minimum number of bits you would need to encode the 26 letters of the alphabet plus a space - a total of 27 characters?

• 2

• 3

• 5

• 6

What order should these be in, from smallest to largest?

1. 01110111₂ 2. 111₁₀                       3. 10000000₂

• 1, 2, 3

• 3, 2, 1

• 3, 1, 2

• 2, 1, 3

Tags

CCSS.6.NS.C.7

What is the best explanation for why digital data is represented in computers in binary?

• The binary number system is the only system flexible enough to allow for representing data other than numbers.

• It's easier, cheaper, and more reliable to build machines and devices that only have to distinguish between binary states.

• It typically takes fewer digits to represent a number in binary compared to other number systems.

• It's impossible to build a computing machine that uses anything but binary to represent numbers.

What is the 4-bit binary number for the decimal number 10?

• 0010

• 1010

• 0110

• 0101

Number systems with different bases such as binary (base-2) and decimal (base-10) are all used to view and represent digital data. Which of the following is NOT true about representing digital data?

• At one of the lowest levels of abstraction, all digital data can be represented in binary using only combinations of the digits zero and one. 

• The same value (number) can have a different representation depending on the number system used to represent it. 

• Groups of bits can be used to represent abstractions, including but not limited to numbers and characters. 

• Some large numbers cannot be represented in binary and can only be represented in decimal.

Which BEST describes metadata?

• It can be compared to a card catalog in the library - not the book itself, but information about the book.

• Information, often quantitative or qualitative, stored by a computer and use in its operations and calculations.

• After or beyond; often used to describe abstraction.

• A collaborative meeting of statisticians, computer programmers, economists, and others at which data are discussed, analyzed, and processed.

Which of the following is a true statement about data compression?

• Data compression is only useful for files being transmitted over the Internet.

• Regardless of the compression technique used, once a data file is compressed, it cannot be restored to its original state.

• Sending a compressed version of a file ensures that the contents of the file cannot be intercepted by an unauthorized user.

• There are trade-offs involved in choosing a compression technique for storing and transmitting data.

A team of researchers wants to create a program to analyze the amount of pollution reported in roughly 3,000 counties across the United States. The program is intended to combine county data sets and then process the data. Which of the following is most likely to be a challenge in creating the program?

• A computer program cannot combine data from different files.

• Different counties may organize data in different ways.

• The number of counties is too large for the program to process.

• The total number of rows of data is too large for the program to process.

Which of the following can be represented by a sequence of bits?

I. An integer

II. A character

III. A sound wave

• I only

• II only

• I and II

• I, II, and III

TikTok has perfected it's FYP by analyzing the data that you spend on the app. The following is a small list of data they have collected: 

● Time and day the user is on the app

●      The hashtags on the videos the user "likes"

●      How long a user watches a certain hashtag

●      What videos the user creates containing hashtags

Which of the following questions CANNOT be answered by looking at the information above?

• How long did a user spend watching #catvideos on Thursday?

• How many videos did the user "like" with #schooliscool?

• Which profile does the user interact with the most?

• Which hashtags does the user like watching at 7am on Wednesdays?