Learn Class 11 Math - Probability

Probability is a numerical measure of the degree of uncertainty in various situations. It can have a positive value ranging from 0 to 1.

The words 'probably,' 'doubt, "most probably,' 'chances,' and so on all have ambiguous meanings.

Probability equals the number of times a favorable event occurs. the total number of outcomes

Probability Approaches:

  • Statistical approach: Data gathering and observation
  • Classical approach: Only equally likely events are considered.
  • Axiomatic technique: This method is used in real-life circumstances. It is closely related to set theory.

Experiments at Random:

  • A variety of outcomes are possible.
  • Knowing the outcome in advance is impossible.

Outcomes:

An outcome is the most likely outcome of a random experiment.

A random experiment has the possibility of producing various outcomes, which is known as sample space. It's represented by the letter S. When a coin flips, for example, the winner is determined by the head.

A sample point is a name given to each member of the sample space. For example, in a coin flip, the head is a sample point.

Event:

  • A series of favorable outcomes is referred to as an event.
  • A subset E of a sample space S is defined as an event.
  • Consider what happens if you roll a dice and get an unexpected outcome.

The occurrence of a specific event:

If the experiment's outcome is that E occurs in a sample space S, E is said to have happened. If the outcome is such that E did not happen, we say that E did not occur.

Probability Sample Questions for Class 11

Question 1

The lock on my luggage has a 4-digit combination. Each digit can be 1-5. If you only have one chance, what is the probability that you guess the correct combination? (Round your answer to 2 decimal places.)
A. 0.16%
B. 0.83%
C. 5.67%
D. 2.35%

Question 2

If you flip a coin 4 times, what is the probability you get heads, heads, tails, heads in that order?
A. 1/8
B. 1/2
C. 1/16
D. 1/32

Question 3

To find the probability of two independent events occurring, you must
A. multiply the elements together.
B. determine the number of elements, then multiply.
C. find the probability of each element, then multiply.
D. divide the number of favorable outcomes by the number of total outcomes.

Question 4

How do you find the total number of arrangements in a permutation?
A. Multiply the elements together.
B. Determine the number of elements, then multiply.
C. Find the probability of each element, then multiply.
D. Divide the number of favorable outcomes by the number of total outcomes.

Question 5

Given a standard deck of 52 cards, what is the probability that, if 5 cards are chosen, 3 are black (spades or clubs) and 2 are red (diamonds or hearts)?
A. 3.3 xx 10^{-1}
B. 1.0 xx 10^{-1}
C. 2.3 xx 10^{-3}
D. 3.8 xx 10^{-6}