Question

The probability of a sure event (or certain event) is
A) 0
B) 1
C) 2
D) 3

Answer 1

Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates impossibility of the event and 1 indicates certainty. The probability formula is used to compute the probability of an event to occur. To recall, the likelihood of an event happening is called probability.
- Probability Rule One (For any event $A, 0 \leq P(A) \leq 1)$
- Probability Rule Two (The sum of the probabilities of all possible outcomes is 1 )
- Probability Rule Three (The Complement Rule)
- Probabilities Involving Multiple Events.
- Probability Rule Four (Addition Rule for Disjoint Events)
- Finding $\mathrm{P}(\mathrm{A}$ and $\mathrm{B})$ using Logic.

Complete step by step solution:
A sure event is an event, which always happens. For example, it’s a sure event to obtain a number between 1 and 6 when rolling an ordinary die. The probability of a sure event has the value of 1. The probability of an impossible event has the value of 0.
An impossible event is an event that cannot happen. E is an impossible event if and only if $\mathrm{P}(\mathrm{E})=0 .$ Example. In flipping a coin once, an impossible event would be getting BOTH a head AND a tail.
A simple (or single) event is an event with a single outcome (only one "answer"). In a simple event, the numerator ("number of times it can occur") will be 1 . A compound event is the combination of two or more simple events (with two or more outcomes).
An event that is certain to happen has a probability of 1. An event that cannot possibly happen has a probability of zero. If there is a chance that an event will happen, then its probability is between zero and 1.
The probability of a sure event is 1.

Hence, the correct answer is option B.

Note:
A probability of 0 means that the event will not happen. For example, if the chance of being involved in a road traffic accident was 0 this would mean it would never happen. We would be perfectly safe. A probability of 1 means that the event will happen. The probability of an event is the number of favourable outcomes divided by the total number of outcomes possible. Converting the fraction 35 to a decimal, we would say there is a 0.6 probability of choosing a banana. This basic definition of probability assumes that all the outcomes are equally likely to occur.
The set of all the possible outcomes is called the sample space of the experiment and is usually denoted by S. Any subset E of the sample space $S$ is called an event. $\ldots \mathrm{E}=\\{2,4,6\\}$ is an event, which can be described in words as "the number is even". Example 3 Tossing a coin twice.