Code.org Unit 2

What does it mean to solve something using a heuristic approach?

• to solve by consulting experts who have previously studied the problem

• to solve within an hour

• to solve a problem with a slow, methodical approach, eliminating poor possibilities one by one as you go.

• to find a solution in a reasonable time frame that is good enough for solving the problem.

What is lossy transformation?

• a transformation that would not let you recover every bit

• a transformation that allows you to recover the original data

• a transformation that fixes the original data

• a transformation that improves the original image

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

• True

• False

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

• True

• False

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

• True

• False

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

• True

• False

How can we represent the number of digits possible if we go from using 8 bits of information for student id #s to using 40 bits of information for student ids?

• 2 times as many values can be represented.

• 32 times as many values can be represented.

• 2^32 times as many values can be represented.

• 32^2 times as many values can be represented.

Which option lists units of bytes from largest to smallest?

• terabyte, gigabyte, kilobyte

• megabyte, terabyte, kilobyte

• gigabyte, terabyte, megabyte

• kilobyte, gigabyte, terabyte

An artist makes an RGB raster image in which each pixel color is encoded with 12-bits --- 4 bits each for red, green and blue.

Which of the following correctly shows the hexadecimal value for Blue as a 12-bit representation.

• F00

• 00F

• 00FF

• 0000FF

A single hexadecimal digit represents a four-bit sequence.

• True

• False