In light-dependent photosynthesis, light quality refers to the wavelengths of light that are important. The wavelength of a sample of photo synthetically active radiations (PAR) is measured to the nearest nanometer. The red range is 675–700 nm and the blue range is 450–500 nm. Let A 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) A Ç B

(d) A È B