Magnetic resonance imaging (MRI) is a process that produces internal body images using a

strong magnetic field. Some patients become claustrophobic and require sedation because they are

required to lie within a small, enclosed space during the MRI test. Suppose that 20% of all patients

undergoing MRI testing require sedation due to claustrophobia. If five patients are selected at random,

find the probability that the number of patients in these five who require sedation is

a. exactly 2 b. none c. exactly 4