Question 1
A podcast platform stores a mono audio preview clip recorded at a sample rate of 22,050 Hz with a bit depth of 16 bits. The clip is 4 minutes long. What is the uncompressed file size of this clip in megabytes (using 1 MB = 1,048,576 bytes)?No clue? Show me the answer
Correct answerCorrect!
IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Approach 1Step 1: Identify the audio parameters
The clip is mono (1 channel), bit depth = 16 bits, sample rate = 22,050 Hz, and duration = 4 minutes = 240 seconds.
Step 2: Apply the audio file size formula
Step 3: Convert bits to bytes
Step 4: Convert bytes to megabytes
Step 5: Select the correct answer
The uncompressed file size is approximately 10.1 MB, matching the first option.
Method #2Approach 2Step 1: Identify what is being asked
We need the uncompressed size of a mono 16-bit audio clip at 22,050 Hz for 240 seconds, converted to MB.
Step 2: Eliminate 'Approximately 20.2 MB'
20.2 MB would result from treating the clip as stereo (2 channels) instead of mono. Since it is explicitly mono, this is incorrect.
Step 3: Eliminate 'Approximately 40.4 MB'
40.4 MB would arise from doubling 20.2 MB, possibly from an error treating it as stereo and miscalculating the duration or bit depth — far too large for mono 16-bit at this sample rate.
Step 4: Eliminate 'Approximately 5.05 MB'
5.05 MB is approximately half of 10.1 MB, which would result from using an 8-bit depth instead of 16-bit, or halving the duration — neither matches the given parameters.
Step 5: Select the correct answer
The only value consistent with 1 channel × 16 bits × 22,050 Hz × 240 s ÷ 8 ÷ 1,048,576 is approximately 10.1 MB.
Question 2
A smart greenhouse system triggers a water pump only when BOTH soil moisture sensor A reads 'dry' (A = 1) AND the rain sensor B reads 'no rain' (B = 1). Which logic gate correctly models this condition?No clue? Show me the answer
Correct answerCorrect!IncorrectStep-by-step walkthrough
Choose a solution method
Method #1Approach 1Step 1: Identify the logical condition
The pump triggers only when A = 1 AND B = 1 — both conditions must be true simultaneously.
Step 2: Match to the AND gate truth table
The AND gate outputs 1 only when all inputs are 1. For all other combinations (A=0,B=0), (A=0,B=1), (A=1,B=0) the output is 0 — exactly matching the requirement.
Step 3: Confirm the answer
The correct gate is the AND gate, as it models the 'both conditions must be met' requirement precisely.
Method #2Approach 2Step 1: Identify what is being asked
We need the gate where the output is 1 only when both inputs are 1.
Step 2: Eliminate OR gate
The OR gate outputs 1 when at least one input is 1. This would trigger the pump even if only one sensor reads active — not matching the requirement.
Step 3: Eliminate XOR gate
The XOR gate outputs 1 when inputs are different. It would trigger the pump when exactly one sensor is active, and not when both are active — the opposite of what is needed.
Step 4: Eliminate NOR gate
The NOR gate outputs 1 only when both inputs are 0. This would trigger the pump when neither sensor is active — clearly incorrect.
Step 5: Select AND gate
Only the AND gate produces output 1 exclusively when both A and B are 1, matching the pump activation condition.