Q. A event which has only ...X... sample point of a sample space, is called simple event. Here, X refers to

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Solution:

If an event has only one sample point of a sample space, then it is called a simple (or elementary) event.
In a sample space containing distinct elements, there are exactly simple events.
For example, in the experiment of tossing two coins, a sample space is

There are four simple events corresponding to this sample space. These are and .