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If the occurrence of some events are dependent on the occurrence of an event A then sum of all the joint

probabilities in which the occurrence of event A is considered gives the

a) Subjective probability of event A

b) Classical probability of event A

c) Conditional probability of event A

d) Marginal Probability of event A

e) Relative frequency of occurrence of event A

d) Marginal Probability of event A

Let us say i have two boxes A and B and both have red balls. Now i want to find the probability of Red ball.Now ball can come from box A and box B.These are mutual exclusive events as ball will come from A or B and collectively exhaustive events.So Bayee's theorem will be applicable here,by which we can say that Probability of Event Red ball(Er) is the sum of joint probabilities of selecting a box and getting Red ball.

Now getting Red ball is the Event A as per your question. And occurrence of Some events from question means  Selecting box 1 and 2,which is depending on the Event of selecting ball Red.So we get here the marginal probability of A

Is marginal probability is in Gate syllabus.

As provided gate syllabus does not contain marginal probability.

A is the event then P(A) is the marginal probability of A :)

The interesting thing about a marginal probability is that the term sounds complicated, but it’s actually the probability that we are most familiar with. Basically anytime you are in interested in a single event irrespective of any other event (i.e. “marginalizing the other event”), then it is a marginal probability. For instance, the probability of a coin flip giving a head is considered a marginal probability because we aren’t considering any other events. Typically, we just say probability and not the marginal part of it because this part only comes into play when we have to factor in a second event.