Answer 1

• If $f_s = 16$, what is the duration shown?
  

• The sampling period (time between samples) is
  $$T_s = 1/16$$    s$$.$$
  Since 24 samples are shown, the duration is
  $$24 \times T_s = \frac{24}{16}= \frac{3}{2} = 1.5$$    s$$.$$

• If $f_s = 32$, the duration is shorter:
  $$24 \times T_s = \frac{24}{32}= \frac{3}{4} = .75$$    s$$.$$