In light-dependent photosynthesis, light quality refers to the wavelengths of light that are important. The wavelength of a sample of photosynthetically active radiations (PAR) is measured to the nearest nanometer. The red range is 675-700 m and the blue range is 450-500 nm. Let 4 denote the event that PAR occurs in the red range and let B denote the event that PAR occurs in the blue range. Describe the sample space and indicate each of the following events:

(a) A

(b) B

(c) 408

(d) R