Answer: Taking into account sound is a wave, we can use the information of the displacement (generally given as a graph) to find the wavelength and frequency, then we can calculate the speed with the formula of the speed of a wave.
Explanation:
If we have the displacement graph of the sound wave, we can find its amplitude, its wavelength and period (which is the inverse of frequency).
Now, if we additionally have the frequency as data, we can use the equation of the speed of a wave:

Where:
is the speed of the sound wave
is the wavelength
is the frequency
(a) 
The frequency of a wave is given by:

where
v is the wave's speed
is the wavelength
For the red laser light in this problem, we have
(speed of light)

Substituting,

(b) 427.6 nm
The wavelength of the wave in the glass is given by

where
is the original wavelength of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,

(c) 
The speed of the wave in the glass is given by

where
is the original speed of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,

Answer:
32 pounds
Explanation:
The amount of water in the 200 pound person is
200 * 60% = 200*0.6 = 120 pounds
Of the 120 pounds, a third of this is extracellular fluid, the amount of extracellular fluid is
120 / 3 = 40 pounds
20 % of this is in the blood, which amounts to
40 * 20% = 40 * 0.2 = 8 pounds
The rest is interstitial fluid, which is
40 - 8 = 32 pounds