Work out sampling rate (nyquist) instantly with clear inputs, formula shown and shareable results.
Nyquist requires a sample rate above twice the highest signal frequency. The gap between the signal edge and half the sample rate is the transition band the anti-alias filter must roll off in, which is exactly why 44.1 kHz was chosen for 20 kHz audio rather than a bare 40 kHz.
Nyquist
fs > 2 x fmax; transition band = fs/2 - fmax; SNR = 6.02n + 1.76 dB
There would be no transition band, requiring an impossible brick-wall filter. Practical designs leave 10-20% headroom or oversample and filter digitally.
Each extra bit halves the quantisation step, and 20log10(2) is 6.02 dB. The 1.76 dB accounts for the uniform distribution of quantisation error.