Which of the following events are disjoint?

a. Choose a student at random from a statistics class. Event A is that the student is a junior. Event B is that the student is a senior.

b. Choose a student at random from a statistics class. Event A is that the student is a psychology major. Event B is that the student is a statistics major.

c. Choose a student at random from a statistics class. Event A is that the student is at least 5'8" tall. Event B is that the student weighs at least 160 pounds.

Step-by-step explanation:

We have to find out which two events are disjoint.

Two events are disjoint if both cannot happen simultaneously or Probability of both occurring is strictly 0.

a) Choose a student at random from a statistics class. Event A is that the student is a junior. Event B is that the student is a senior.

These are disjoint because a student cannot be a senior and junior both.

b) Choose a student at random from a statistics class. Event A is that the student is a psychology major. Event B is that the student is a statistics major.

Disjoint because same student cannot have psychology as well as statistics as major

c. Choose a student at random from a statistics class. Event A is that the student is at least 5'8" tall. Event B is that the student weighs at least 160 pounds.

These cannot be disjoint because there are chances for some students to be taller than 5 feet 8 inches and also having weight more than 160 lbs.